JP2006350908A - Optical information input device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an input device for effectively detecting an instruction to a region where an observation angle of retroreflection light from a light emitting part of an instructing part is within a fixed angle. <P>SOLUTION: The input device is constituted of an instruction unit having a retroreflector installed in a limited region, a sensor in which the visual field of direct light from the instruction unit to the sensor is limited and a wide area light emitting part of the instruction unit provided with the retroreflector installed in a limited region, a sensor having wide area light receiving sensitivity and a light emitting part having a one-way directivity in which direct light to the sensor is not always emitted. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical information processing apparatus that controls an apparatus by irradiating light including operation information of an operation unit and receiving the light. Specifically, the present invention relates to a device configuration in a case where the operable range is set to a certain range in a remote operation device (so-called remote controller).

  Furthermore, the present invention provides, for example, a coordinate input device, more specifically, for controlling a connected computer or writing characters or figures by inputting coordinates by pointing to the input surface with an indicator or the like. This is a coordinate input device used, and extends to a technique for improving the operation range.

  Further, among the coordinate input devices, the present invention relates to a retroreflected light shielding type coordinate input device in which a retroreflective material is provided around the input surface and the indicated position coordinates are input by detecting a light shielding state by an indicator or the like. It extends to.

  Conventionally, as a means to control various devices wirelessly from a remote location, a signal light modulated with switch information from a light source such as an LED is emitted from an operation unit, that is, a so-called remote controller, and a photodiode or photo IC. A technique of receiving light by a sensor such as a signal, demodulating by a calculation circuit, and performing remote operation is generally a widely known technique. The operable range of the remote controller is naturally determined by the combination of the light emission intensity and light emission directivity of the light source and the light reception sensitivity and light reception range characteristics of the sensor.

  The operation unit applies not only to the so-called remote controller but also to a pen-shaped instruction unit of the coordinate input device. In other words, the operation information in this case includes so-called pen up / down information indicating whether or not the pointing tool of the coordinate input device has touched the input surface, or switching information of the pointing tool. It becomes important information when writing characters.

  Conventionally, various types of coordinate input devices such as digitizers or touch panels have been proposed or commercialized, making it easy to operate a PC on the screen without using special equipment. Since it can be used, it is widely used.

  There are various methods such as a method using a resistance film and a method using ultrasonic waves. As shown in Patent Document 1 as a method using light, the method recurs outside the coordinate input surface. In a configuration in which a light reflecting means is provided, the light from the means for illuminating light is reflected by the retroreflective sheet, and the light quantity distribution is detected by the light receiving means, the area of the input area that is shielded by an indicator or a finger It is known to detect the angle and determine the coordinates of the shielding position, that is, the input position.

  Further, as in Japanese Patents Nos. 2 and 3, the retroreflective member is configured around the input region, and a device for detecting the coordinates of the portion where the retroreflected light is shielded is disclosed. .

  In these apparatuses, for example, in Patent Document 2, the angle of the light-shielding part is detected by detecting the peak of the light-shielding part by waveform processing calculation such as differentiation, and in Patent Document 3, comparison with a specific level pattern is performed. Shows a configuration in which one end and the other end of the light shielding portion are detected and the center of the coordinates is detected.

  Further, in Patent Document 1, when each pixel of the RAM imager is read and compared by a comparator, a light-shielding portion is detected, and when there is a light-shielding portion having a certain width or more, the centers of the pixels at both ends thereof are detected. A detection method for detecting (1/2 position) is shown.

In Patent Literature 4, Patent Literature 5, and Patent Literature 6, light emission and emission ranges are controlled as devices that control the light receiving and emitting ranges in the optical coordinate input device configured with the retroreflective member as described above around the input region. A device for controlling the range is shown. These light receiving and emitting ranges are inventions related to coordinate information, and basically are intended to be controlled by the optical characteristics of the light receiving and emitting unit itself, and the light receiving and emitting units are generally at the same distance to the coordinate input surface. Even when the light emitting / receiving unit is arranged in a region of a saddle structure that forms a frame around the coordinate input surface, for example, the optical path range of the light receiving / emitting unit is the distance to the coordinate input surface. Since this is limited to a certain range that is almost the same as the portion, the problem of vignetting that the optical path related to the coordinate information is blocked by the eyelids and that cannot be operated is generated on the optical path. On the contrary, if the light receiving / emitting range related to the coordinate information is widened, it is easily affected by disturbance light.
U.S. Pat.No. 4,507,557 Japanese Unexamined Patent Publication No. 2000-105671 Japanese Patent Laid-Open No. 2001-142642 JP 2001-33125 A JP 2000-207126 A JP 2001-290583 A

  In a remote control device using a so-called remote controller configured to irradiate a signal light modulated with switch information from a light emitting source such as a conventional LED as described above and receive the light with a sensor such as a photodiode or a photo IC, the operation range thereof Is determined by a combination of a wide light emission directivity of the light source and a wide light receiving range characteristic of the sensor, and therefore, as shown in FIG. 19, a wide input possible range A becomes a problem in normal use. However, it has been difficult to perform control such as further restricting the operation range (input possible range B) such that the operation can be performed only by a certain target person. In other words, in order to limit the operation range to a certain range, it is necessary to narrow the light reception range, and it is conceivable to select one with a narrow sensitivity distribution of the sensor itself, but the sensitivity distribution of the light reception sensor itself compared to the device on the light emission side If the sensor is narrow, the selection range such as the wavelength is usually limited due to the characteristics of the lens, etc., and if a sensor with a normal sensitivity distribution is used, the optical sensor such as the lens on the light receiving side of the sensor is used. Although a method for adding a mechanical mechanism is conceivable, the configuration becomes complicated and the cost increases accordingly. A field stop may be simply provided, but similarly, the number of parts increases and the field of view expands depending on the distance. The light emission directivity on the issue side is usually sharpened as the light emission range B as shown in the figure, or irradiated with parallel light etc. by a collimator lens etc., and the light emission range is limited and narrowed, When operating an operation unit such as a remote control, the posture changes in various ways, so the operator must always move the operation unit parallel to the light emitting direction, that is, the operation unit must be kept at a constant posture. It was not practical.

In the present invention, in order to solve the above problem, an operation unit including a light emitting unit that emits light including operation information;
A retroreflecting material that recursively reflects light emitted from the operation unit;
Only the retroreflected light from the light emitting unit of the operation unit, or further, an operation information light receiving unit that receives direct light from the light emitting unit in addition to the retroreflected light,
The observation angle at which the retroreflected light of the light emitted from the light emitting unit effectively reaches the operation information light receiving unit (the angle formed by the retroreflected light with respect to the incident angle from the light emitting unit with respect to the retroreflective material) is within a certain angle. The effective operation area is defined in the range of the above, or the effective operation area by the retroreflected light of the operation unit based on the observation angle range effectively reaches the operation information light receiving unit of the direct light from the operation unit The configuration is such that it is added to the effective operation area based on the range. With this pointing device configuration of the present invention, it is possible to limit the operation range to a desired range without providing a special optical mechanism in the light emitting / receiving unit. Furthermore, a desired area can be newly added as an operable range to the conventional operable range.

  As described above, in the present invention, an operation unit including a light emitting unit that emits light including operation information, a retroreflecting material that recursively reflects light emitted from the operation unit, and light emission of the operation unit. A retro-reflected light of the light emitted from the light-emitting unit, the operation information light-receiving unit receiving only the retro-reflected light from the light-receiving unit or the direct light from the light-emitting unit in addition to the retro-reflected light The effective operation region is defined in a range where the observation angle that effectively reaches the operation information light receiving unit (the angle formed by the retroreflected light with respect to the incident angle from the light emitting unit with respect to the retroreflective material) is within a certain angle, or The effective operation area by the retroreflected light of the operation unit based on the range of the observation angle is added to the effective operation area based on the range that effectively reaches the operation information light receiving unit of the direct light from the operation unit. The feature is as follows. With this configuration of the present invention, it is possible to set a very narrow desired range as an inputable area for an operation without using a conventional complicated optical mechanism.

  Further, in the present invention, a plurality of coordinate information light receiving portions are provided at the corners of the coordinate input area surface, and the retroreflective material is provided at the periphery of the coordinate input area surface, and projects light onto the retroreflective material. The amount of light detected by the coordinate information light receiving unit when the light from the light projecting unit provided in the periphery of the coordinate input area surface and the light reflected from the retroreflective material is blocked by an indicator or the like. An optical system that has an angle detection means for detecting the direction indicated by the pointing tool from the change, and calculates position coordinates on the coordinate input area surface pointed to by the pointing tool based on the derived plurality of angle information In the information input device, the operation information light receiving unit is disposed in a collar member that limits the field of view of the operation information light receiving unit in a shape that covers the entire circumference or part of the periphery of the coordinate input area surface, The unit is the pointing tool and includes the operation information Is disposed at a distance equal to or larger than the opening height of the flange member from the tip of the indicating unit, and the operation information indicates a contact state of the pointing tool to the coordinate input area surface. By using the configuration including the information or the indicator switch information, the retroreflective material can be used easily for the coordinate input detection and the operation information detection for the pointing tool, without increasing the number of parts. A highly accurate optical coordinate input device can be realized with the configuration. Furthermore, since the input possible range based on the observation angle by the retroreflective material is very limited, the light receiving / emitting range related to the operation information can be minimized as much as possible, and the influence of ambient light is reduced. be able to. At the same time, since the light receiving / emitting range related to the coordinate information is not expanded, the influence of disturbance light can be suppressed without impairing the input operation feeling related to the coordinate input.

  Next, details of the present invention will be described in accordance with the description of the embodiments.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
A schematic configuration of an optical information processing apparatus according to the present invention will be described with reference to FIGS. 1 (1) to 1 (3). In FIG. 1 (1), 6 is a light emitting part having a light emission directivity characteristic having a certain degree of spread, 3 is a retroreflective material having a certain width, and 1 is not shown in the figure, but the conventional example of FIG. It is a light receiving section having a sensitivity range characteristic having a normal spread in one direction. Although not shown in the drawing, the light emitting unit 6 is attached to an operation unit such as a so-called remote controller. For example, the light source 6 is held by a hand to irradiate a certain target. Accordingly, the direct light from the light emitting unit 6 of the operation unit is irradiated in the direction of the retroreflecting material 3 and thus does not reach the light receiving unit 6 in the opposite direction. In the vicinity of the target, a belt-like retroreflective material 3 having a certain width W is attached. This retroreflective material is a reflective material that is generally used for traffic signs, etc., and has the property of being reflected in the incident direction of light. The combination of beads and reflective surfaces, or the principle of retroreflection such as corner cubes It is a reflection sheet shape using Thus, although the light is originally reflected in the incident direction due to the nature of the retroreflective material, actually, the reflected light is also generated in a direction slightly deviated from the incident angle. The angle formed by the reflected light with respect to the incident angle of the incident light is called an observation angle. For example, the angle α shown in FIG. 1A is an observation angle when light is emitted from the light emitting unit 6 and is retroreflected by the retroreflecting material 3 and received by the light receiving unit 1. The amount of reflected light is halved at a very slight angle of about 0.5 ° for the corner cube structure and about 1 ° for the bead structure. Of course, strictly speaking, this observation angle characteristic differs depending on the structure and material of each retroreflective material. Accordingly, in the side view of the present invention in FIG. 1 (1), if the lower limit value of the light receiving sensitivity of the light receiving unit 1 is L, the influence of the current distance is ignored, and the light emission distribution of the light emitting unit is constant. Assuming that there is a light emitting part of the operating part within an angle αL range where the observation angle α is not less than the limit value L of the light receiving sensitivity of the light receiving part 1, that is, a range where α ≦ αL, the light receiving part 1 Is received and can be operated effectively. This effective operation area is set as an inputable range. As a result, the influence of the distance is simplified in FIG. 1 (1), but as seen from the side, the observation angle α is in a very narrow range where α ≦ αL and is almost in the vicinity of the retroreflective material. It is possible to set a substantially band-like inputable area that becomes the width W of the retroreflective material. The width W of the retroreflective material is increased or decreased according to the required range of the inputable area. Actually, the effect of distance is added to this, and as the optical path becomes shorter as the retroreflective material 3 is approached, the attenuation of the amount of light disappears and the amount of spectrum increases. The range is slightly larger than the region where α ≦ αL. Strictly speaking, since the retroreflective member 3 has a width W, the incident angle is different within the input range. Therefore, the amount of retroreflected light decreases as the incident angle increases. Since the distance between the light receiving unit 1 and the retroreflecting material 3 is small, the influence of this incident angle can be almost ignored. The direction of the side view of the present embodiment is a direction intended to enable an input operation only in a certain narrower range such as the input possible region.

  In the plan view, as shown in FIG. 1 (2), for example, the retroreflective material 3 is disposed at a concentric circular arc centered on the light receiving unit 1. The direction of the plan view here is, for example, a direction that gives a certain range of size to the human operation direction, which will be described later with reference to FIG. With this arrangement, the incident angle depending on the position of the light emitting unit 6 of the operation unit is always constant (almost 0 °), so the influence of the plane direction due to the change of the incident angle can be almost ignored. In the case of this configuration, the input range in the planar direction is a sector-shaped range + α formed by the arc in which the concentric retroreflecting material 3 with the light receiving unit 1 as the center is arranged. The range of + α is a range in which the range satisfying the observation angle α ≦ αL is further added outside the linear portion of the radius at both ends of the fan-shaped range.

  In the present embodiment, the retroreflecting material 3 is arranged at a concentric circular arc centered on the light receiving unit 1 in the direction of the plan view, but may be arranged on a straight line although not shown in the drawing. In this case, the input possible range is not determined by the length on which the retroreflective material 3 is arranged on a straight line, but within the range where the observation angle α ≦ αL, and the reflected wave that is effective in the light receiving unit 1. It is determined by the characteristics of the incident angle at which the amount of light is obtained. That is, as the incident angle increases, the amount of light reflected decreases, so that the light receiving portion 1 determined by the observation angle characteristics and the incident angle characteristics of the retroreflecting material 3 is the apex, and the retroreflecting material 3 is the base. This is a triangular input range.

  Next, when the operator actually operates the light emitting unit 6 in the embodiment in which a desired input possible area is set by the configuration of the light receiving unit 1, the retroreflective member 3 and the light emitting unit 6 described above of the present invention. The target will be specifically described with reference to FIG. The target in this case is a display installed on a wall or the like. This display device assumes a case where a large number of display devices such as an exhibition are installed in a venue. The light emitted from the light emitting unit of the operation unit is received by the light receiving unit 1, and the received operation information controls the display through the control device. The height direction of the display unit is made to correspond to the height direction of the side view of FIG. 1 (1), and it is intended that the input operation only in a certain narrower range is effective in this direction.

  A visitor who is an operator possesses an operation unit as a remote controller, and when he / she comes in front of a display which is a target exhibit, starts a desired operation before the display. The light receiving unit 1 is installed on the opposite side of the display. Moreover, the retroreflective material 3 is installed in the lower part of the display in the above state. Even if there is no room for placing a large device in the space in the vicinity of the display, the retroreflective material 3 has almost no thickness and can be easily installed at a desired operating range. In this configuration, as shown in FIG. 1 (3) (not shown in the plane direction but the same as shown in FIG. 1 (2)), this is determined by the arrangement of the retroreflecting material 3 and the light receiving unit 1. The input possible range is set, and the operator operates in front of the display that is the target exhibit and operates the operation unit within the input possible range to emit the light receiving unit 1 toward the retroreflective material 3. Only in the case where the light is received, the light containing the operation information can be received effectively by the light receiving unit 1 and the operation can be performed. The operation information in this case includes, for example, display page turning, screen switching, selection from a menu, and mouse operation in a normal personal computer. Therefore, it is possible to avoid interference due to operations in the vicinity of other exhibits. Further, as shown in FIG. 1 (3), even if a child or the like operates with mischief, the input range in the height direction is recursively described above. Since it is intentionally narrowly defined by the reflector 3, it cannot be operated when it does not reach this range, and malfunction can be prevented.

(Second embodiment)
In the first embodiment, an embodiment relating to an input possible range using an operation unit such as a remote controller is shown. However, the light emitting unit 6 adopts the basic configuration of the present invention not only in the remote controller but also in the optical coordinate input device. May be arranged in a pen-shaped indicator, the retroreflective member 3 in the peripheral part of the coordinate input area surface, and the light receiving part 1 in the collar member in the peripheral part of the coordinate input area surface. This configuration will be described with reference to FIGS. 2 (1) and 2 (2).

  In the figure, reference numerals 10L and 10R denote sensor units having a light projecting means 11 and coordinate information light receiving / detecting means 12, which are installed at a predetermined distance apart. The sensor unit is connected to a control / arithmetic unit 2 that performs control / calculation, receives a control signal from the control / arithmetic unit, and transmits a detected signal to the control / arithmetic unit. Reference numeral 3 denotes a retroreflecting material, which is a reflecting means having a retroreflecting surface that reflects incident light in the direction of arrival as shown in FIG. 2 (3), and is within a range of approximately 90 ° from the light projecting means 11 of the left and right sensor units 10. The light projected on is retroreflected toward the sensor unit. The reflected light is detected one-dimensionally by the coordinate information detecting means 12 of the sensor unit constituted by a condensing optical system and a line CCD, and the light amount distribution is sent to the control / arithmetic unit. The retroreflecting material 3 also serves as a retroreflecting material for the light from the light emitting unit 6 provided in a pen-shaped indicator 6-1 described later. The characteristics of the retroreflecting material itself are as described in the first embodiment.

  Reference numeral 5 denotes a coordinate input surface, which includes a display screen 4 of a display device such as a PDP, a rear projector, an LCD panel, or a front plate 4 ′ (not shown) that is a substantially transparent plate disposed on the front surface of the display screen 4. Therefore, it can be used as an interactive input device.

  In such a configuration, when an input instruction is given to the input area using the pen-shaped indicator 6-1 shown in the figure, the light projected from the light projecting means is blocked, and the peripheral frame retroreflecting means 3 Therefore, it becomes impossible to obtain the reflected light due to the retroreflection from the light source, so that the light quantity cannot be obtained only at the input instruction position. The arithmetic control means of the main unit detects the light-shielding range of the input instructed part from the light quantity change of the left and right sensor units, specifies the detection point within the same range, and calculates the respective angles. The coordinate position on the input area is calculated from the calculated angle and the distance between the sensor units.

  In the light emitting / receiving range related to coordinate detection, the distance from the coordinate input surface directly affects the operational feeling of coordinate input as it is. In other words, if the distance from the coordinate input surface becomes too large, it may cause tailing when writing characters, and conversely if it is too short, cursor control at a place slightly away from the coordinate input surface called proximity will be performed. It becomes impossible. Therefore, the light receiving / emitting range related to the coordinate detection is such that the light projecting means 11 and the coordinate information light receiving / detecting means 12 constituting the sensor unit are installed with a distance as small as possible, and the retroreflective material 3 is recursive with an observation angle of 0 °. Reflected light, which is determined by the sensor unit and the width of the retroreflective material and the retroreflective material, which are arranged at a constant short distance from the coordinate input surface, for example, the same distance within a range of about 0 to 10 mm. An inputable range is formed as the light emission range. Therefore, with respect to this coordinate detection, even if the sensor unit is arranged inside the cover ridge formed in the shape of a frame around the coordinate input area surface, the coordinate input surface does not cover the light emitting / receiving range. Therefore, the so-called vignetting, in which the light rays are blocked by the folds, is not generated. In addition, the limitation of the light emitting / receiving range also serves to prevent the influence of ambient light.

  The above is the description of the configuration relating to the input coordinate detection of the optical coordinate input device according to the second embodiment of the present invention. Next, the input of the operation information of the pointing tool 6-1 will be described. The operation information includes so-called pen up / down information indicating whether or not the pointing tool of the coordinate input device has touched the input surface, or switch information of the pointing tool. In particular, a command is sent to a computer or a character is written. It becomes important information when doing. As shown in FIG. 2 (2), the indicator 6-1 includes whether or not the pen tip contacts the coordinate input surface 5, that is, a pen up / down switch, or a pen side switch (not shown), Further, an arithmetic circuit (not shown) that processes the ON / OF information of the switch, a light-emitting unit driving circuit (not shown) that superimposes this information on the driving signal, and light emitted at a certain timing driven by the driving circuit. A light emitting unit 6 is incorporated. The light emitting unit 6 has a light irradiation range that extends in the direction of the normal line with respect to the axis of the indicator 6-1 and is substantially centered in the 360 ° circumferential direction around the axis. For example, six LEDs are arranged radially so that light can be emitted uniformly. Of course, the configuration of the light emitting unit may be other than six as long as a light emission distribution that does not hinder the operation is obtained, and the light emitting member includes a light guide material, an optical mechanism, a diffusion mechanism, and the like. The structure which added can also be used. When the light emitted from the light emitting unit 6 of the pointing tool 6-1 is retroreflected by the retroreflecting material 3 disposed in the peripheral part of the coordinate input surface 5, and the incident angle and the observation angle satisfy a certain condition. Then, the light is received and detected by the light receiving unit 1 arranged in the peripheral part of the coordinate input surface 5. Due to the characteristics of the retroreflective material 3 of the present invention, the retroreflective material 3 is located around the coordinate input surface 5, but the sensor unit 10 having the light projecting means 11 and the coordinate information light receiving / detecting means 12 and the light receiving unit 1 are It is arranged on a side or area that is not installed. Further, in the configuration of the optical coordinate input device of the present invention, the sensor unit 10 and the light receiving unit 1 are arranged around the coordinate input surface in order to prevent the influence of disturbance light and protect from damage due to external force. It is arranged inside the cover collar 13 as shown in the figure. FIG. 2B, which is a cross-sectional view of the present invention viewed from the side, shows the positional relationship between the flange 13 and the light receiving unit 1. Therefore, the light receiving unit 1 is limited in the light receiving range by the flange 13, and the light receiving range from the coordinate input surface 5 becomes narrower as it approaches the flange 13 as shown in the figure. Now, it is assumed that the vertical dimension of the opening of the heel 10 (the distance from the coordinate input surface 5 to the lower end of the heel 10) C is set.

  On the other hand, the light emitting unit 6 is related to the mechanism of the tip of the pointing device 6-1 (accommodating a pen tip replacement material and its holding member, and a slide mechanism and switches for the pen tip switch mechanism). In addition, there is a limit to disposing the light emitting unit 6 near the tip of the indicator 6-1. As a result, as shown in the figure, the distance D from the tip of the indicator of the light emitter 6 is increased, and the indicator When 6-1 is instructed perpendicular to the coordinate input surface 5, a relationship of C <D is established. Therefore, as shown in the drawing, when the pointing tool 6-1 inputs coordinates at the position A away from the sensor unit 10, that is, the eyelid 13, the light emitting unit 6 that emits light in a 360 ° direction perpendicular to the axis. Since the direct light F on the light receiving unit 1 side from the light enters the effective light receiving range of the light receiving unit 1, an effective light amount is detected, but the indicator 6-1 is located at the position B in the vicinity of the sensor unit 10, that is, the eaves 13. When the coordinates are input at, the direct light F on the light receiving unit 1 side from the light emitting unit 6 emitting light in a 360 ° direction perpendicular to the axis of the indicator 6-1 is blocked by the eaves 13 and received by the light receiving unit. Therefore, the effective light quantity is not detected. In the present invention, when coordinates are input at the position B near the ridge 13, the light from the light emitting unit 6 emitting light in a 360 ° direction perpendicular to the axis is received by the light receiving unit 6. 1 enters the retroreflective material 3 disposed around the coordinate input surface 5 on the substantially opposite side to 1. The observation angle α formed by the retroreflection angle of the retroreflected light with respect to the light receiving unit 1 with respect to the incident angle on the retroreflecting material 3 is within the angle at which an effective light amount can be obtained in the dimension of the coordinate input surface 5. It is possible to receive signal light including operation information. In the characteristics of the retroreflective material provided around the coordinate input area surface 5, when the observation angle α = 1 ° and half the light amount of α = 0 °, the half light amount is the limit of the light receiving sensitivity. In the present invention, in the present invention, the retroreflecting material from the light emitting unit 6 in the vicinity of the ridge 13 that cannot receive the direct light from the light emitting unit 6 when the pointing device 6-1 is pointed perpendicular to the coordinate input surface 5 is used. 3, the mounting position of the retroreflective material 3, that is, the dimension of the coordinate input surface 5, the distance from the tip of the indicator 6-1 of the light emitting unit 6, so that the observation angle to the light receiving unit 1 with respect to The position of the light receiving unit 1 is determined. Strictly speaking, the observation angle α with respect to the retroreflecting material 3 and the light receiving unit 1 increases as the indicator 6-1, that is, the light emitting unit 6 moves away from the light receiving unit 1, that is, the ridge 13, and accordingly the retroreflected light from the light emitting unit 6 is increased. The amount of light received by the light receiving unit 1 decreases, and conversely, the direct light F from the light emitting unit 6 to the light receiving unit 1 increases, so that the retroreflected light receivable region and the direct light receivable region are shown in FIG. The mounting position of the retroreflective material 3, that is, the dimension of the coordinate input surface 5, the distance from the tip of the light emitting unit 6 to the indicator 6-1 and the position of the light receiving unit 1 are determined so that there is an overlapping region. . That is, the observation angle at a position where direct light from the light emitting unit 6 to the light receiving unit 1 cannot be obtained is arranged such that the limit angle is 1 ° or less. As a result, a region where the retroreflected light receivable region is added to the direct light receivable region becomes the input receivable range. That is, the present invention is not limited to the conventional configuration that uses retroreflected light with an observation angle of 0 °, which is a basic idea of the light receiving and emitting range related to coordinate input, and the retroreflected light of the retroreflective material has an observation angle of Paying attention to the fact that retroreflected light can be obtained with a certain angle width that may be 0 ° or more, the range of the observation angle where the required amount of light can be obtained corresponds to the light receiving and emitting range related to operation information It is a related invention.

  The above has been described based on the observation angle of the retroreflected light of the retroreflecting material 3 in a plane perpendicular to the coordinate input surface 5, but the range of the observation angle at which the necessary light quantity can be obtained is the coordinate input surface. Similarly, a plane parallel to 5 has a width of an observation angle corresponding to the light quantity range, and therefore there is a certain inputable range in a region parallel to the coordinate input plane 5. Further, the width direction of the retroreflective material has a narrow dimension, whereas the length direction along the side of the coordinate input area 5 has a long dimension, and therefore corresponds to the observation angle range corresponding to the effective light amount range. There is a certain range in the area of the retroreflective material, and the sum of the area of the retroreflective material within this range contributes to the pointing position of a certain indicator 6-1. However, as shown in the first embodiment, it is not common to arrange the retroreflecting material 3 in a circular arc shape with the light receiving portion 1 being the center of a concentric circle, and usually a square shape as shown in FIG. Since the linear retroreflective material is arranged at the positions of the sides around the coordinate input surface 5, the light quantity of the retroreflected light becomes small in the range where the incident angle is large, and therefore the operation corresponding to the effective light quantity range is possible. Since the range becomes small, in order to make the retroreflected light effective in the entire coordinate input area 5, the incident angle to the retroreflective material 3 corresponding to the effective range of the received light quantity is within a certain angle. As described above, a plurality of the light receiving portions 1 are installed at necessary places.

  Furthermore, not only the incident angle but also a sufficient amount of light cannot be obtained due to the vignetting of 13 directly in the vicinity of the ridge 13 of the coordinate input surface 5, and the observation angle in the vertical direction with respect to the coordinate input surface is large and effective. For an input region where only the retroreflective material that is out of the range exists, a position where the retroreflective material whose observation angle is newly within the effective range is present, specifically, a plane parallel to the coordinate input surface 5 , The retroreflecting material is present on the extension of the line segment connecting the indication position of the indicator 6-1 in the coordinate input surface 5 and the light receiving unit 1 and is perpendicular to the coordinate input surface 5. The light receiving unit 1 is arranged at a position where the distance of the retroreflecting material 3 can be sufficiently taken from the indication position of the indicator 6-1 so that the observation angle is within an angle range (for example, within 1 degree) where the effective light amount is obtained. To do. That is, in the first half of the above description, the effective observation angle is determined by the effective light amount depending on the positional relationship among the light receiving unit 1, the indicator 6-1 and the retroreflective member, and therefore, the effective operation range (effective input range). However, conversely, even if the required positional relationship among the light receiving unit 1, the indicator 6-1 and the retroreflective member is determined from the necessary effective operation range (effective input range). Good.

  As described above, in the second embodiment of the present invention, the retroreflective member is used for both coordinate input detection and operation information detection of the pointing tool, and has a simple configuration without increasing the number of parts. A highly accurate optical coordinate input device can be realized. Furthermore, since the input possible range based on the observation angle by the retroreflective material is very limited, the light receiving / emitting range related to the operation information can be minimized as much as possible, and the influence of ambient light is reduced. be able to. At the same time, since the light receiving / emitting range related to the coordinate information is not expanded, the influence of disturbance light can be suppressed without impairing the input operation feeling related to the coordinate input.

  In this way, it is possible to input the pen up / down of the pointing tool and other switch information at the same time as inputting the coordinates with the pointing tool etc., so that the PC can be used for drawing lines on the screen, operating switches, icons, etc. Can be operated.

  Hereinafter, each part will be described in detail with a focus on the part relating to coordinate input detection in the second embodiment of the present invention other than the operation information on the pointing tool.

<Detailed explanation of sensor unit>
FIGS. 3A and 3B are configuration examples of light projecting means in the sensor unit.

  FIG. 3 (1) is a view of the light projecting unit viewed from above (perpendicular to the input surface). In the figure, reference numeral 31 denotes an infrared LED that emits infrared light, and the emitted light is projected by a light projection lens 32 in a range of approximately 90 °. On the other hand, FIG. 3 (2) is a view of the same configuration seen from the side. In this direction (horizontal with respect to the input surface), in this direction, the light from the infrared LED 31 is projected as a light beam restricted in the vertical direction. Mainly, light is projected to the retroreflective means 3.

  FIG. 4 is a view of the detection means in the sensor unit as viewed from the direction perpendicular to the input surface.

  The detection means includes a one-dimensional line CCD 41, lenses 42 and 43 as a condensing optical system, and a diaphragm 44 that limits the incident direction of incident light. As described above, an infrared filter 45 that prevents the incidence of extraneous light such as visible light may be added.

  The light from the light projecting means is reflected by the retroreflective member, passes through the infrared filter 45 and the diaphragm 44, and the light in the approximately 90 ° range of the input surface is incident on the CCD detection surface by the condensing lenses 42 and 43. An image is formed on the pixel depending on the angle, and the light amount distribution for each angle is shown. That is, the pixel number represents angle information.

  FIG. 5 shows a configuration in which the light projecting unit and the detection unit are overlapped to form the sensor unit 1 when viewed from the horizontal direction with the input surface.

  The distance between the optical axes of the light projecting means and the detecting means may be set in a range that can be sufficiently detected from the angular characteristics of the retroreflective member.

<About reflective members>
The retroreflective member 3 shown in FIGS. 2 (1), 2 (2), and 2 (3) has reflection characteristics with respect to the incident angle.

  When the retroreflective tape is configured flat as shown in FIG. 6, the amount of reflected light obtained from the angle from the reflective member exceeding 45 degrees decreases, and the change occurs when there is a shield. Will not be enough.

  The amount of reflected light is determined by the light amount distribution (illumination intensity and distance), the reflectance of the reflecting member (incident angle, the width of the reflecting member), and the imaging system illuminance (cosine fourth law).

  If the amount of light is insufficient, it is conceivable to increase the illumination intensity. However, if the reflection distribution is not uniform, when a strong portion of light is received, that portion is saturated by the CCD, which is the light receiving means. There is a limit to increasing the illumination intensity.

  In other words, it is possible to increase the amount of light incident on the low light amount portion by making the reflection distribution of the reflecting member as uniform as possible.

  In order to make the angle direction uniform, the member to which the retroreflective member 3 is attached has a shape in which triangular prisms are arranged as shown in FIG. 7, and the retroreflective member 3 is installed thereon. By doing so, the angle characteristics can be improved. The angle of the triangular prism may be determined from the reflection characteristics of the retroreflective member, and the pitch is preferably set to be equal to or less than the detection resolution by the CCD. The structure of the peripheral frame retroreflective member 3 itself is constituted by a bead type, a corner cube type, or a prism or the like as described above.

<Description of control / arithmetic unit>
Between the control / arithmetic unit and the sensor units 1L, 1R in FIG. 2A, a CCD control signal, a CCD clock signal and a CCD output signal, and an LED drive signal are exchanged.

  FIG. 8 is a block diagram of the control / arithmetic unit. The CCD control signal is output from an arithmetic control circuit 83 constituted by a one-chip microcomputer or the like, and performs CCD shutter timing, data output control, and the like. The CCD clock is sent from the clock generation circuit 87 to the sensor unit, and is also input to the arithmetic control circuit 83 in order to perform various controls in synchronization with the CCD.

  The LED drive signal is supplied from the arithmetic control circuit 83 to the infrared LEDs of the sensor unit through the LED drive circuits 84L and 84R.

  Detection signals from the CCD, which is the detection means of the sensor unit, are input to the AD converters 81L and 81R of the control / arithmetic unit, and are converted into digital values under the control of the arithmetic control circuit.

  The converted digital value is stored in 82 memory and used for angle calculation.

  From the calculated angle, a coordinate value is obtained and output to an external PC or the like via the serial interface 88 or the like.

<Explanation of light intensity distribution detection>
FIG. 9 is a timing chart of control signals.

  Reference numerals 91, 92, and 93 denote control signals for CCD control, and the shutter release time of the CCD is determined by the interval of 91SH signals. Reference numerals 92 and 93 denote gate signals to the left and right sensors, respectively, which are signals for transferring the charge of the photoelectric conversion unit in the CCD to the reading unit.

  Reference numerals 94 and 95 denote left and right LED drive signals, and 94 drive signals are supplied to the LEDs through the LED drive circuit in order to light one LED in the first cycle of SH. The other LED is driven in the next cycle. After the driving of both LEDs is completed, the CCD signal is read from the left and right sensors.

  When the signal to be read is not input, a light amount distribution as shown in FIG. 10 is obtained as an output from each sensor. Of course, such a distribution is not necessarily obtained in any system, and the distribution changes depending on the characteristics of the retroreflective means 3, the characteristics of the LEDs, and changes in time (such as dirt on the reflecting surface).

  In the figure, the A level is the maximum light amount, and the B level is the lowest level.

  In other words, in a state where there is no reflected light, the level obtained is near B, and the direction of the A level increases as the amount of reflected light increases. In this way, the data output from the CCD is sequentially AD converted and taken into the CPU as digital data.

  FIG. 11A is an example of output when input is performed with a conventional pointing tool or finger, that is, when reflected light is blocked.

  Since the reflected light is blocked by the conventional indicator or finger at the portion C, the amount of light is reduced only at that portion.

  Specifically, an initial state without input as shown in FIG. 10 is stored in advance, and whether there is a change as shown in FIG. 11 in each sample period is detected by the difference from the initial state. An operation for determining an input angle is performed using that portion as an input point.

<Explanation of angle calculation>
In calculating the angle, it is first necessary to detect the light shielding range.

  As described above, since the light quantity distribution is not constant due to changes in timekeeping, it is desirable to store it when the system is started. By doing so, for example, even if the retroreflective surface is dirty with dust or the like, it can be used unless it is not completely reflected.

  Hereinafter, data of one sensor will be described, but the same processing is performed on the other.

  When the power is turned on, the CCD output is first AD-converted without illumination from the light projecting means without input, and this is stored in the memory as Bas_data [N]. This is data including variations in CCD bias and the like, and is data near the level B in FIG. Here, N is a pixel number, and a pixel number corresponding to an effective input range is used.

  Next, the light quantity distribution in the state illuminated from the light projecting means is stored. This data is represented by the solid line in FIG. 10 and is Ref_data [N].

  Using these data, it is first determined whether an input has been made or whether there is a light shielding range.

  Data of a certain sample period is assumed to be Norm_data [N].

  First, in order to specify the light shielding range, presence / absence is determined based on the absolute amount of data change. This is to prevent erroneous determination due to noise or the like and to detect a certain amount of reliable change.

  The absolute amount of change is calculated for each pixel as follows and compared to a predetermined threshold value Vtha.

Norm_data_a [N] = Norm_data [N] −Ref_data [N] (1)
Here, Norm_data_a [N] is an absolute change amount in each pixel.

  Since this process only takes a difference and compares it, it does not use much processing time, and therefore it is possible to determine whether or not there is an input at high speed.

  When the number of pixels exceeding the threshold value Vtha for the first time is detected exceeding a predetermined number, it is determined that there is an input.

  Next, in order to detect with higher accuracy, a change ratio is calculated to determine an input point.

  Here, assuming that the reflectance of the A area has decreased due to dirt or the like, the distribution of Ref_data [N] at this time has a smaller amount of reflected light in the A area as shown in FIG. In this state, when an indicator or the like is inserted as shown in FIG. 12 and almost half of the retroreflective member is covered, the amount of reflected light is substantially halved, which is indicated by the thick lines in FIGS. 13 (1) and (2). Distribution Norm_data [N] is observed.

  If (1) is applied to this state, the result is as shown in FIG. Here, the vertical axis represents the differential voltage from the initial state.

  If a threshold is applied to this data, the original input range may be lost. Of course, it can be detected to some extent if the threshold value is lowered, but it may be affected by noise or the like.

  Therefore, if the ratio of change is calculated, the amount of reflected light is half of the first half in both the A area and the B area.

Norm_data_r [N] = Norm_data_a [N] / (Bas_data [N]-Ref_data [N]) (2)
This calculation result is as shown in FIG. 14 (2), and is represented by a variation ratio. Therefore, even when the reflectance is different, it can be handled equally, and detection can be performed with high accuracy.

  The threshold value Vthr is applied to this data, and the angle is determined from the pixel numbers of the rising and falling portions with the center of both as the input pixel.

  FIG. 14 (2) is schematically drawn for explanation, and does not actually rise like this, but shows a different level for each pixel.

  FIG. 15 shows an example of detection after the ratio calculation is completed. Assume that when the detection is made with the threshold value Vthr, the rising portion of the light shielding area exceeds the threshold value at the Nrth pixel. Furthermore, it is assumed that the voltage falls below Vthr at the Nf-th pixel.

Keep the center pixel Np
Np = Nr + (Nf-Nr) / 2 (3)
However, in this case, the pixel interval becomes the minimum resolution.

  In order to detect more finely, a virtual pixel number across the threshold is calculated using the level of each pixel and the level of the previous pixel.

The level of Nr is now Lr. The level of Nr-1 pixel is Lr-1. Further, if the level of Nf is Lf and the number Nf-1 is Lf-1, the virtual pixel numbers Nrv and Nfv are
Nrv = Nr-1 + (Vthr-Lr-1) / (Lr-Lr-1) (4)
Nfv = Nf-1 + (Vthr-Lf-1) / (Lf-Lf-1) (5)
Virtual center pixel Npv
Npv = Nrv + (Nfv Nrv) / 2 (6)
Determined by

  Thus, by calculating a virtual pixel number from the pixel number and its level, detection with higher resolution can be performed.

  In order to calculate an actual coordinate value from the obtained center pixel number, it is necessary to convert it into angle information.

  In actual coordinate calculation described later, it is more convenient to obtain the value of the tangent at the angle rather than the angle itself.

  A table reference or a conversion formula is used for conversion from the pixel number to tan θ.

  FIG. 16 is a plot of tan θ values against pixel numbers. An approximate expression is obtained for this data, and pixel number and tan θ conversion is performed using the approximate expression.

  For example, when a high-order polynomial is used as the conversion formula, the accuracy can be ensured, but the order and the like may be determined in consideration of the calculation capability and accuracy specifications.

  When a fifth order polynomial is used, six coefficients are required, so this data may be stored in a nonvolatile memory or the like at the time of shipment.

If the coefficients of the fifth-order polynomial are now L5, L4, L3, L2, L1, L0,
tanθ is
tanθ = (L5 * Npr + L4) * Npr + L3) * Npr + L2) * Npr + L1) * Npr + L0 (7)
Can be represented.

  If the same thing is done for each sensor, the respective angle data can be determined.

  Of course, in the above example, tan θ is obtained, but the angle itself may be obtained, and then tan θ may be obtained.

<Description of coordinate calculation method>
Coordinates are calculated from the obtained angle data.

  FIG. 17 is a diagram showing a positional relationship with the screen coordinates.

  Each sensor unit is mounted on the left and right sides of the input range, and the distance between them is expressed as Ds.

  The center of the screen is the origin position of the screen, and P0 is the intersection of the angle 0 of each sensor unit.

  The respective angles are θL and θR, and tanθL and tanθR are calculated using the above polynomials.

At this time, the x and y coordinates of point P are
x = Ds * (tanθL + tanθR) / (1+ (tanθL * tanθR)) (8)
y =-Ds * (tanθR-tanθL-(2 * tanθL * tanθR)) /
(1+ (tanθL * tanθR)) + P0Y (9)
Calculated by

<Flow chart showing the process from data acquisition to coordinate calculation>
FIG. 18 is a flowchart showing steps from data acquisition to coordinate calculation.

  When the power is turned on in S101, various initializations such as port setting of the arithmetic control circuit and timer setting are performed. S103 is a preparation for removing unnecessary charges that is performed only at startup. In a photoelectric conversion element such as a CCD, unnecessary charge may be accumulated when it is not operated. If the data is used as it is as reference data, it becomes impossible to detect or causes false detection. In order to avoid this, data is first read multiple times without illumination. In S103, the number of times of reading is set. In S104, unnecessary data is removed by reading the data a predetermined number of times without illumination.

  S105 is a judgment sentence for repeating a predetermined number of times.

  S106 is fetching of data without illumination as reference data, and corresponds to the above Bas_data.

  The data fetched here is stored in the memory and used for calculation thereafter.

  This and another reference data, data Ref_data corresponding to the initial light amount distribution when illuminated, are taken in S108, and this is also stored in the memory.

  Up to this step is the initial setting operation when the power is turned on, and then the normal capturing operation is performed. In S110, the light amount distribution is taken in as described above, and in S111, the presence / absence of a light-shielding portion is determined based on the difference value from Ref_data. If it is determined that there is no data, the process returns to S110 and capture is performed.

  At this time, if the repetition period is set to about 10 [msec], the sampling rate is 100 times / second.

  If it is determined in S112 that there is a light-shielding area, the ratio is calculated by the processing of Expression (2) in S113. A rising portion and a falling portion are determined by a threshold with respect to the obtained ratio, and the numbers are stored in a memory S114. Next, the center is calculated by the equations (4), (5) and (6). At this time, as described above, the first rising portion and the last falling portion are used for the calculation in S115. Tan 116 is calculated from the obtained central value by an approximate polynomial, and x and y coordinates are calculated from the Tan θ values of the left and right sensor units using equations (8) and (9) S116. Next, it is determined whether or not it is touched in S117. For example, a proximity input state in which the cursor is moved without pressing a mouse button and a touch-down state in which the left button is pressed are determined. Actually, if the maximum value of the ratio obtained previously exceeds a certain predetermined value, such as 0.5, it is determined to be down, and if it is less than that, the proximity input state is determined. According to this result, down flag setting S118 or reset S119 is performed.

  Since the coordinate value and the down state are determined, the data is transmitted to the host PC S120. This may be sent by serial communication such as USB, RS232, etc., or by any interface. On the PC side, the driver interprets the data and moves the cursor, changes the mouse button state, etc. by referring to the coordinate values, flags, etc., so that the PC screen can be operated.

  When the processing of S120 is completed, the processing returns to S110, and thereafter this processing is repeated until the power is turned off.

1 is a schematic configuration diagram of an optical information processing apparatus according to a first embodiment of the present invention. 2 is an overall schematic configuration diagram of an optical information processing apparatus according to a second embodiment of the present invention. Configuration example of light projecting means in sensor unit A view of the detection means in the sensor unit viewed from the direction perpendicular to the input surface Configuration when the light projection means and the detection means are overlapped to form the sensor unit 1 when viewed from the horizontal direction with the input surface. Relationship between the amount of reflected light and the reflection angle when the retroreflective tape is flat. Retroreflective members in the shape of triangular prisms Block diagram of control / arithmetic unit Control signal timing chart Diagram showing light intensity distribution Light intensity distribution when input is performed with an indicator Diagram showing light-shielding state Reflected light intensity distribution chart Reflected light intensity distribution chart Example of detection after ratio calculation Plot of tanθ value against pixel number Diagram showing positional relationship with screen coordinates Flow chart showing the process from data acquisition to coordinate calculation The figure which shows the operation range of the conventional remote control device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light-receiving part 2 Control / arithmetic unit 3 Retroreflective material 5 Coordinate input surface 6 Light-emitting part 6-1 Pointer 13 Cover cover arrange | positioned around coordinate input surface

Claims (2)

An operation unit including a light emitting unit that emits light including operation information;
A retroreflecting material that recursively reflects light emitted from the operation unit;
Only the retroreflected light from the light emitting unit of the operation unit, or further, an operation information light receiving unit that receives direct light from the light emitting unit in addition to the retroreflected light,
The observation angle at which the retroreflected light of the light emitted from the light emitting unit effectively reaches the operation information light receiving unit (the angle formed by the retroreflected light with respect to the incident angle from the light emitting unit with respect to the retroreflective material) is within a certain angle. The effective operation area is defined in the range of the above, or the effective operation area by the retroreflected light of the operation unit based on the observation angle range effectively reaches the operation information light receiving unit of the direct light from the operation unit An optical information input device added to an effective operation area based on a range. In the optical information input device according to claim 1, a plurality of coordinate information light receiving portions are provided at corners of the coordinate input region surface, and the retroreflective material is provided at a peripheral portion of the coordinate input region surface. By projecting light on the coordinate input area surface that projects light onto the retroreflective material, light from the light projecting unit reflected by the retroreflective material is blocked by an indicator or the like A coordinate input area surface designated by the pointing tool or the like based on a plurality of derived angle information, having angle detecting means for detecting a direction pointed by the pointing tool or the like from a change in the amount of light detected by the coordinate information light receiving unit. While calculating the position coordinates at
The operation information light receiving unit is disposed in a collar member that limits the field of view of the operation information light receiving unit in a shape that covers the entire circumference or part of the periphery of the coordinate input area surface, and the operation unit is the indicator. A light-emitting unit that emits light including the operation information is disposed at a distance equal to or greater than the opening height of the flange member from the tip of the indicating unit, and the coordinates of the pointing tool are input to the operation information. An optical information input device including information indicating a contact state with an area surface or indication unit switch information.

Images