JP2009021018A - Operation input device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable operation input device of excellent operability and handleabiity realizing sure inputting of operation with a finger. <P>SOLUTION: This device includes light emitting elements 7a to 7c disposed on the rear of a key switch operation surface of a translucent plate 4 to emit lights of different colors, a light receiving element 9 detecting light emitted from the light emitting element and reflected from the finger 5 having touched the front of the key switch operation surface of the plate 4, a wavelength selecting means 12 selecting one of the light emitting elements 7a to 7c, a memory means 14 storing the received amount of light from the selected light emitting element at each wavelength and a judging means 15 judging whether the key switch operation surface is operated from the received light amount stored at each wavelength. Detection of the operation from the received light amounts at different wavelengths realizes sure inputting of operation with the finger to provide the highly reliable device of excellent operability and handleability. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical operation input device in household appliances and the like.

Conventionally, as an operation input device for household appliances and the like (for example, induction heating cooker, jar rice cooker, water heater, washing machine, heating device, and other devices), a touch panel type having a drip-proof function (for example, a patent) A capacitance type (see, for example, Patent Document 2) or an optical type (for example, see Patent Document 3) with a lighter feeling of operation and higher confidentiality is known.
JP-A-6-209849 Japanese Patent Laid-Open No. 10-214677 JP 2000-100287 A

  However, among the above-mentioned conventional configurations, in the touch panel type, due to the limitation of the heat resistance temperature of the film material in the operation panel integrally molded with the waterproof film, the pan that has become hot during cooking (up to 350 ° C when fried) is directly adjusted. I can't put it. Further, in the capacitance type, even when seasoning liquid or water is spilled on the top plate, it is accepted as an operation input. Further, in the optical system, when a reflector other than the finger to be operated, such as a cloth or paper, is mistakenly placed on the key switch operation surface, it is accepted as an operation input. As described above, both methods have problems in operation and handling.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object thereof is to provide a reliable operation input device that enables reliable operation input by finger operation, has excellent operability and handleability.

  In order to solve the above-described conventional problems, an operation input device according to the present invention includes a translucent plate having a key switch operation surface and a plurality of light beams having different peak wavelengths arranged on the back side of the key switch operation surface of the plate. A light emitting element that emits light; a light receiving element that detects reflected light reflected by a reflector that touches the front side of the key switch operation surface on the plate; and a wavelength selection unit that selects the light emitting element. A storage means for storing the received light amount from the light emitting element selected by the wavelength selecting means for each wavelength; and a determination for determining whether or not the key switch operation surface is operated from the received light amount at each wavelength stored in the storage means Means.

  Thus, by detecting the presence / absence of an operation from the amounts of received light between different wavelengths, a reliable operation input by a finger operation is possible, and the operability and handling are excellent and the reliability is high.

  The operation input device of the present invention enables reliable operation input by finger operation, is excellent in operability and handling, and has high reliability.

  According to a first aspect of the present invention, there is provided a translucent plate having a key switch operation surface, a plurality of light emitting elements arranged on the back side of the key switch operation surface of the plate and emitting light having different peak wavelengths, and light from the light emitting elements. A light receiving element for detecting reflected light reflected by a reflector touching the front side of the key switch operation surface on the plate, a wavelength selecting means for selecting the light emitting element, and a light emitting element selected by the wavelength selecting means The operation input device includes a storage means for storing the received light amount for each wavelength and a determination means for determining whether or not the key switch operation surface is operated from the received light amount at each wavelength stored in the storage means. is there. Thus, by detecting the presence / absence of an operation from the amounts of received light between different wavelengths, a reliable operation input by a finger operation is possible, and the operability and handling are excellent and the reliability is high.

  In particular, the second invention has the first light emitting element and the second light emitting element having different wavelengths in place of the light emitting elements that emit light having different peak wavelengths in the first invention. It is excellent in operability and handling and is highly reliable.

  In the third invention, in particular, in the second invention, by setting the wavelength on the short wavelength side to 0.65 μm or less, it is possible to more reliably detect the presence or absence of an operation with a finger.

  In the fourth invention, in particular, in the second or third invention, since the wavelength on the long wavelength side is set to less than 1.5 μm, reliable operation input sensitive to only a finger is possible without being sensitive to water. It becomes possible.

  According to a fifth aspect of the invention, in particular, in any one of the first to fourth aspects of the invention, the key switch operation surface is provided with a concave portion for finger operation, and the light emitting element and the light receiving element are arranged corresponding to the concave portion. In addition to improving operability, the influence of ambient light is reduced, and reliable operation input is possible. In particular, this is effective when the key switch operation surface is an inclined surface or a curved surface.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
1 and 2 illustrate an operation input device for an induction heating cooker as the operation input device in Embodiment 1 of the present invention.

  As shown in FIG. 1, the operation input device in the present embodiment is a translucent heat-resistant tempered glass having a key switch operation surface 1, a heating power amount display unit 2, and a heating region unit 3 indicated by a ring pattern. The plate 4 which consists of etc. is provided. In the heating area 3 on the plate 4, an object to be heated such as a pan or a frying pan is placed and cooked. Key switches 1a to 1c are printed on the key switch operation surface 1 of the plate 4, and the user confirms a picture (icon) indicating the control content of the cooking device printed on the key switches 1a to 1c, A cooking operation is performed by touching one of the icons with the finger 5.

  On the circuit board 6 on the back side of the plate 4, a plurality of light emitting elements 7 a to 7 c provided for the key switches 1 a to 1 c, and light from the light emitting elements 7 a to 7 c is on the front side of the key switch operation surface 1 on the plate 4. And a single light receiving element 9 for receiving reflected light of a plurality of wavelengths reflected by the human finger (reflector) 5 touched by the light. Each of the plurality of light emitting elements 7a to 7c irradiates light having different wavelengths with different peak wavelengths.

  Further, on the circuit board 6, in addition to the light emitting elements 7a to 7c and the light receiving element 9, wavelength selection means 12 for switching the wavelengths of the light emitting elements 7a to 7c and selecting the light emitting elements 7a to 7c shown in FIG. The IV conversion means 13 for converting the photocurrent received by the light receiving element 9 into a voltage, the key switches 1a to 1c output from the IV conversion means 13, and a voltage (E1a) proportional to the received light amount for each wavelength , E2a, E1b, E2b, E1c, E2c), and from the output of the storage means 14, the received light amount ratio (E1a / E2a, E1b / E2b, E1c / E2c) of the reflected light of each wavelength is obtained. A discriminating means 15 is provided for calculating and discriminating whether or not the key switches 1a to 1c are operated.

  Further, a V-shaped light guide 10 is provided between the light emitting elements 7 a to 7 c and the plate 4 and between the plate 4 and the light receiving element 9. Between the plate 4 and the light guide 10, the optical adhesive 11 is filled so as not to sandwich the air layer in order to efficiently propagate the irradiation light and the reflected light from the human finger 5. The light emitting elements 7a to 7c, the light receiving element 9, and the light guide 10 are fixed so as to face the circuit board 6 at a predetermined angle.

  The light guide 10 is made of a material having a value close to the refractive index (≈1.541) of the plate 4. For example, polycarbonate whose refractive index has been controlled (under a low refractive index), resin whose sulfur or fluorine is contained in an epoxy resin, and whose content is controlled (controllable with an accuracy of ± 0.001), or amorphous A high-quality transparent plastic polyolefin resin and a composite resin of a plurality of elements are used. Thereby, almost all of the light emitted from the light emitting elements 7 a to 7 c is irradiated on the finger 5 without being reflected by the lower surface of the plate 4. Further, the light receiving element 9 side of the light guide 10 is an elliptical light beam that is calculated so that the optical path to the light receiving element 9 of the reflected light is almost equal no matter where the human finger 5 touches the key switches 1a to 1c. The object plane (x2 / a2 + y2 / b2 = 2z) or the hyperbolic paraboloid (x2 / a2-y2 / b2 = 2z) is used. Since the refractive index of the light guide 10 is matched to the refractive index of the plate 4, most of the reflected light reflected by the human finger 5 is guided to the light receiving element 9 while totally reflecting or traveling straight inside the light guide 10. As a result, the S / N ratio can be kept high.

  About the induction heating cooking appliance comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  The user places a pan or the like that can be induction-heated on the heating area 3 on the plate 4 indicated by the ring pattern. When the power outlet is inserted into the commercial power supply, a key input permission signal and a driving voltage are supplied from a main control circuit (not shown), and the light emitting elements 7a to 7c selected by the wavelength selection unit 12 sequentially emit light having different peak wavelengths. Irradiates and key operation becomes possible. When there is no reflector on the key switches 1a to 1c, the irradiation light enters from the end face of the light guide 10, propagates through the light guide 10 while repeating straight or total reflection, and then passes through the plate 4 Permeated and released to the sky. At this time, since the reflected light is not received by the light receiving element 9, the amount of reflected light E1a≈E2a≈E1b≈E2b≈E1c≈E2c≈ As the result of calculating the light quantity ratio corresponding to each of the key switches 1a to 1c, it is determined that all the key operations are not performed, and no key input signal is output. Not done.

  Next, when a reflector such as the finger 5 is present on the key switch 1b, for example, the irradiation light is diffusely reflected by the finger 5 and the like, and the inside of the light receiving side paraboloid of the light guide 10 is reflected. After propagating in a straight line or with total reflection, the light is received by the light receiving element 9, a photocurrent flows due to the photoelectric effect, and voltages E 1 b and E 2 b proportional to the amount of reflected light are output from the IV conversion means 13 and stored in the storage means 14. Remembered. The discriminating means 15 calculates the stored reflected light quantity ratio E1b / E2b, discriminates that the key switch 1b has been operated, and outputs the key input signal b.

  The main control circuit inputs this key input signal b and starts a heating operation by electromagnetic induction. Similarly, when there is a reflector such as the finger 5 on the key switch 1a, the heating power is lowered, and when there is a reflector such as the finger 5 on the key switch 1c, the heating power is increased. When the cooking is finished and the user touches the key switch 1b with the human finger 5 again, the heating operation is stopped.

  Here, by matching the refractive index of the light guide 10 provided between the light emitting element 9 and the plate 4 serving as the key switch operation surface 1 with the plate 4, the reflected light reflected by the reflector such as the human finger 5. Is guided to the light receiving element 9 by the shape of the light receiving side paraboloid of the light guide 10, so that the amount of received light is stable, and reliable operation input is possible even through the plate 4.

  As described above, in the present embodiment, two types of light having different wavelengths are emitted from each of the light emitting elements 7a to 7c, the ratio of the amount of reflected light received is calculated, and the presence or absence of an operation is detected. This enables reliable operation input by finger operation, is excellent in operability and handling, and is highly reliable. In particular, the influence input to disturbance light, a change with time of the light emitting element, or the like is reduced, and a highly reliable operation input device can be obtained.

  The operation input means of this embodiment is optical and does not require any operating force (it can be operated by simply touching a finger without touching it). It is semi-permanent, has a feature of being able to have a dustproof and waterproof structure, is strong against dirt on the operation surface of the key switch, and has high reliability.

  Further, in this embodiment, there is no protective film on the key switch operation surface, and there is no attenuation while the reflected light from the human finger is transmitted. Can be done.

  The light emitting elements 7a to 7c may be two-color (RG, RB, BG) light-emitting LEDs or three-color (full color) LEDs, and may sequentially emit light at a plurality of different wavelengths.

  In addition, since a high-speed key switch response such as a game machine is not required but rather a reliable operation input is required, the number of key switches x multiple wavelengths x pulse width = total input time, compared to conventional input devices However, no problem occurs even if the input time is long.

  Further, the wavelength selection unit 12, the storage unit 14, and the determination unit 15 may be realized by an inexpensive microcomputer with a small number of pins in which ROM, RAM, I / O, and A / D are integrated on one chip.

(Embodiment 2)
3 to 5 show the absorption characteristics of hemoglobin and moisture contained in the operation input device and the human finger according to the second embodiment of the present invention. The same elements as those of the operation input device in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIGS. 3 and 4, the operation input device in the present embodiment is a first light emitting element having a different wavelength instead of the light emitting elements 7 a to 7 c that emit light having different peak wavelengths in the first embodiment. 8a to 8c and second light emitting elements 8d to 8f. Specifically, out of the wavelength light of 0.5 μm to 3.5 μm, the first light emitting elements 8a to 8c emit light on the short wavelength side, and the second light emitting elements 8d to 8f are light on the long wavelength side. Is emitted. The light emitting elements 8a and 8d, 8b and 8e, and 8c and 8f are arranged in pairs.

  Further, as shown in FIG. 3, the V-shaped light guide 10 includes a light incident guide portion 10 a that guides light from the light emitting elements 8 a to 8 c and 8 d to 8 f to the key switch operation surface 1, and a human finger 5. The reflection guide portion 10b guides the reflected light to the light receiving element 9, and performs total reflection due to the difference in refractive index between the constituent material (refractive index = 1.541) and air (refractive index = 1). By utilizing this, light is efficiently guided to the key switch operation surface 1 and the light receiving element 9. That is, the transmittance of the plate 4 <the transmittance of the portion of the optical adhesive 11 in contact with the plate 4 <the transmittance of the light incident guide portion 10a is designed. As a result, the light emitted from the first light emitting elements 8a to 8c and the second light emitting elements 8d to 8f is guided from the light incident guide portion 10a to the plate 4 with almost no reflected light. On the other hand, the light reflected by the reflector such as the human finger 5 does not return to the light incident guide portion 10a because the total reflection condition is satisfied, and most of the light is guided to the light receiving element 9 by the reflection guide portion 10b. Thus, the S / N ratio (ratio of reflected light and disturbance light, ratio with and without key operation) can be kept high.

  Next, when a reflector such as the human finger 5 is present on the key switches 1a to 1c, the irradiation light is diffusely reflected by the human finger 5 or the like and travels straight inside the light receiving side paraboloid shape of the reflection guide portion 10b. Alternatively, after propagating while repeating total reflection, light is received by the light receiving element 9, a photocurrent flows due to the photoelectric effect, and voltages E 1 a to E 1 c proportional to the amount of reflected light from the IV conversion means 13 (the amount of reflected light by the first light emitting element). ), E2a to E2c (the amount of light reflected by the second light emitting element) are output and stored in the storage means 14. The discriminating means 15 calculates the stored reflected light quantity ratios E1a / E2a, E1b / E2b, E1c / E2c, discriminates that the key switches 1a to 1c are operated, and outputs key input signals a to c.

  Further, as shown in FIG. 5, hemoglobin is strongly absorbed in the visible light region of 0.65 μm or less, and moisture is strongly absorbed in the region exceeding 1.5 μm. About 70% of human tissue is occupied by water, and considering that it is mainly water and hemoglobin that absorbs light in the visible to infrared regions in the living body, it is 0.65 μm or less and 1. Light in the wavelength range of less than 5 μm (near infrared light) is suitable for human body detection. On the other hand, the tempered glass used for the plate 4 of the induction heating cooker increases the strength while having heat resistance. Therefore, a crystallized glass in which fine crystals are precipitated by reheating the glass having a special composition is used. The light with a wavelength of 0.5 μm to 2.6 μm is transmitted 80% or more, the light with a wavelength of 3 to 4 μm is transmitted about 30%, a wavelength longer than 4 μm and a wavelength shorter than 0.5 μm. Since light hardly passes, LEDs having a wavelength of 0.563 μm (pure green) or a wavelength of 0.591 μm (yellow) are used as the first light-emitting elements 8a to 8c, and wavelengths 1 and 2 are used as the second light-emitting elements 8d to 8f. A laser diode of about 1 μm can be used. As the light receiving element 9, PIN-PD or the like can be used.

The reflection characteristics of the object for detecting presence / absence of key operation are arranged as follows.
1. Human fingers (oxygenated hemoglobin, water)
1. Both an absorption spectrum of oxyhemoglobin (0.65 μm or less) and a moisture absorption spectrum (1.5 μm or more) are shown. 2. Absorption spectrum (1.5 μm or more) of spilled water or cooking liquid water on the key switch operation surface of the plate. Pan (metal, earthenware) placed on the key switch operation surface of the plate
Therefore, when the first light emitting elements 8a to 8c are irradiated, the reflected light is small, and when the second light emitting elements 8d to 8f are irradiated, it can be determined that there is a reflected light as the finger 5.

  As described above, in the present embodiment, 0.65 μm or less is applied to the first light emitting elements 8 a to 8 c that emit light on the short wavelength side (λ1 in FIG. 5) out of the wavelength light of 0.5 μm to 3.5 μm. The elements having the wavelengths are sequentially turned on by using elements of less than 1.5 μm (and 0.65 μm or more) as the second light emitting elements 8d to 8f that emit light on the long wavelength side (λ2 in FIG. 5), By calculating the ratio of the amount of light received by the single light receiving element 9, a highly reliable operation input device sensitive only to the human finger 5 can be obtained.

  Since the operation method is a fingertip, the temperature range of the key switch operation surface 1 that is sufficiently cooled by the intake air generated by the blower fan built in the cooking device is maintained at 0 to 40 ° C. This key switch operation surface 1 The infrared energy radiated by the plate 4 itself is concentrated to a wavelength of 3.5 μm to 65 μm according to Stefan-Boltzmann law. In addition, the temperature of cooking pans and the like is about 30 ° C to 350 ° C, and the infrared peak wavelength emitted by an object at this temperature is 5 µm to 10 µm according to Planck's radiation law. According to the law, it is collected to 1.8 μm to 65 μm. Among these, a light shielding material (not shown) is provided so that infrared light of 1.8 μm to 4 μm penetrates the plate 4 and enters the outer shell of the cooker body, but does not enter the light receiving element 9 directly. .

  In addition, induction heating is connected in parallel to the first smoothing capacitor from a commercial power source through a diode bridge, and after converting this DC voltage into a high-frequency current by an inverter circuit, a predetermined gap is provided facing a pan or the like. A high frequency magnetic field is generated by supplying it to the heating coil that is arranged, and a pan or the like is inductively heated. For this reason, since there is a lot of electromagnetic induction noise such as high-frequency current supplied to the heating coil and switching noise of the DC power supply, noise removal processing (delay) time is provided for detection of photocurrent to prevent malfunction. Generally, a cooking device does not require a fast key switch response like a game machine, but rather requires a reliable operation input, so the number of key switches x multiple wavelengths x pulse width = total input There is no problem even if the time and the input time are longer than those of the conventional input device.

  As described above, in the present embodiment, since the first light emitting elements 8a to 8c and the second light emitting elements 8d to 8f having different wavelengths are provided, the operability and the handling are further improved. It will be highly reliable.

(Embodiment 3)
FIG. 6 illustrates an operation input device of a jar rice cooker as an operation input device in Embodiment 3 of the present invention. The same elements as those of the operation input device in the first and second embodiments are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in the figure, the operation input device in the present embodiment is provided with a finger operation recess 16 on the key switch operation surface 1, and the light emitting elements 7 a to 7 c (or 8 a to 8 c, 8 d) corresponding to the recess 16. To 8f) and the light receiving element 9 are arranged. The recess 16 preferably has an elliptical shape that matches the shape of the human finger. As a result, the operational feeling is improved and the influence of disturbance light is reduced, thereby enabling reliable operation input.

  Since the main operations in the jar rice cooker are “cooking start / stop” and “heat retention / off”, as shown in the two recesses 16 in FIG. The operation input device (including the recess 16, the light emitting element and the light receiving element) in the embodiment is assigned, and the remaining time setting keys and course selection keys are used as conventional waterproof film type push switches so as to reduce costs. If it is not necessary to consider the cost, all the switches can be the operation input device in this embodiment.

  The illustrated jar rice cooker includes a body 17, a pot 18 for adding rice and water, a temperature sensor 19 for detecting the temperature of the pot 18, an operation board 20, and an operation input in this embodiment provided on the inclined surface of the upper surface of the body 17. The apparatus includes a heating control circuit board 21 for induction heating and waterproof film type push switches 22a to 22d.

  As described above, in this embodiment, by providing the finger switch recess 16 on the key switch operation surface 1, the operability is improved and the influence of ambient light is reduced, thereby enabling reliable operation input. Become. In particular, this is effective when the key switch operation surface is an inclined surface or a curved surface.

  As described above, the operation input device according to the present invention enables reliable operation input by finger operation, has excellent operability and handling, and is highly reliable. It can also be applied to various industrial equipment.

(A) Top view of the induction heating cooking appliance which has the operation input device in Embodiment 1 of this invention (b) Sectional drawing of the principal part of the operation input device Block diagram of the operation input device (A) Side sectional view of main part of operation input device according to embodiment 2 of the present invention (b) Related configuration diagram of light guide and light receiving element of operation input device Block diagram of the operation input device Graph showing the correlation between absorbance and wavelength of reflector (A) The side view which showed the principal part of the jar rice cooker which has the operation input apparatus in Embodiment 3 of this invention in the cross section, (b) The top view which shows the operation part of the jar rice cooker, (c) Same operation input Cross section of the main part of the device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Key switch operation surface 4 Plate 5 Finger 7a-7c Light emitting element 8a-8c 1st light emitting element 8d-8f 2nd light emitting element 9 Light receiving element 12 Wavelength selection means 13 IV conversion means 14 Storage means 15 Discriminating means 16 recess

Claims (5)

A translucent plate having a key switch operation surface, a plurality of light emitting elements arranged on the back side of the key switch operation surface of the plate and emitting light having different peak wavelengths, and a key switch on which light from the light emitting elements is on the plate A light receiving element that detects reflected light reflected by a reflector touching the front side of the operation surface, a wavelength selecting unit that selects the light emitting element, and a received light amount from the light emitting element selected by the wavelength selecting unit by wavelength. An operation input device comprising: storage means for storing; and determination means for determining presence / absence of operation of the key switch operation surface from received light amounts at respective wavelengths stored in the storage means. The operation input device according to claim 1, further comprising a first light emitting element and a second light emitting element having different wavelengths instead of the light emitting elements that emit light having different peak wavelengths. The operation input device according to claim 2, wherein the wavelength on the short wavelength side is set to 0.65 μm or less. The operation input device according to claim 2 or 3, wherein the wavelength on the long wavelength side is less than 1.5 µm. The operation input device according to any one of claims 1 to 4, wherein a concave portion for finger operation is provided on the key switch operation surface, and a light emitting element and a light receiving element are arranged corresponding to the concave portion.