JP2015198615A - Plant cultivation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plant cultivation device capable of improving utilization efficiency of light at low cost.SOLUTION: A plant cultivation device 1 comprises: a cultivation vessel 4 which has a cultivation surface 7 on a boundary with plants 5 to be cultivated, holds the plants 5 to be cultivated and feeds at least moisture to the plants; a light source (a part of light source part 2) which emits light; a scanning part (a part of light source part 2) which allows light emitted from the light source toward at least one of the plants to be cultivated or the cultivation surface of the cultivation vessel; a light receiving part 3 which receives light reflected from at least one of the plants 5 to be cultivated or the cultivation surface 7 of the cultivation vessel 4; and a control part which changes light volume of light source on the basis of a light receiving state of the light receiving part 3. When the control part determines that the plants 5 to be cultivated are irradiated with light from the scanning part, it increases light volume of the light source, and when the control part determines that the cultivation surface 7 of the cultivation vessel 4 is irradiated with light from the scanning part, it decreases light volume of the light source.

Description

  The present invention relates to a plant cultivation apparatus for cultivating a plant by artificial lighting.

When plants are cultivated outdoors, the degree of growth is likely to be affected by the natural environment such as the climate, and the yield may be reduced due to damage such as typhoons and heavy rains, or damage caused by pests.
Moreover, in order to raise a certain amount of harvest in cultivation of these plants, since a large land area is required, it becomes difficult to ensure a sufficient cultivation area in a narrow land.

  Therefore, technology for cultivating plants by artificial lighting has been developed and put into practical use as a plant factory. In such plant cultivation, the cost required for lighting is particularly important and occupies a large proportion of 30 to 50% of the whole factory. For this reason, in recent years, light-emitting diodes (LEDs) with low power consumption have been used in place of light bulbs and fluorescent lamps.

  In addition, the use of a semiconductor laser, which is expected to further reduce power consumption, has attracted attention.

Japanese Patent No. 4015251

  However, simply using a semiconductor laser as the light source cannot sufficiently reduce the cost required for illumination.

  This invention is made | formed in order to solve the said subject, Comprising: It aims at providing the plant cultivation apparatus which can improve the utilization efficiency of light at low cost.

  The present invention is a plant cultivation device that promotes the growth of a plant, has a cultivation surface on the boundary with a plant to be cultivated, holds a plant to be cultivated and supplies at least moisture, and light. A light source that emits light, a scanning unit that directs light emitted from the light source to at least one of the cultivation surface of the plant to be cultivated or the cultivation tank, and light reflected from at least one of the cultivation surface of the plant to be cultivated or the cultivation tank And a control unit that changes the light amount of the light source based on the light reception status of the light receiving unit, and the control unit determines that the light to be cultivated is irradiated on the plant to be cultivated The plant cultivation apparatus is characterized in that the light amount of the light source is sometimes increased and the light amount of the light source is decreased when it is determined that the light from the scanning unit is irradiated on the cultivation surface of the cultivation tank.

  According to the present invention, the light receiving unit receives both the light reflected from the plant to be cultivated and the light reflected from the cultivation surface of the cultivation tank, and the light reflected from the plant to be cultivated and cultivation of the cultivation tank. The light reflected from the surface can be distinguished.

  Furthermore, when it is determined that the light from the scanning unit is irradiated on the plant to be cultivated, the light amount of the light source is increased, and when it is determined that the light from the scanning unit is irradiated on the cultivation surface of the cultivation tank Since the light amount of the light source is reduced, the light amount is changed depending on whether the light from the light source contributes to the growth of the plant or not, and the light use efficiency of the light source when growing the plant is increased. be able to.

Perspective view showing plant cultivation equipment Diagram showing the configuration of the light source The figure which shows the structure of the scanning part contained in a light source part Diagram showing the configuration of the light receiving unit The figure which shows the integrated structure of a light source part and a light-receiving part The figure which shows the method of detecting the light quantity of the plant and the cultivation surface of the cultivation tank The figure which shows the method of detecting the distance between the plant and the cultivation surface of the cultivation tank The figure which shows the irradiation state of a plant cultivation apparatus The figure which shows the irradiation state of a plant cultivation apparatus

  The invention according to claim 1 is a plant cultivation device that promotes the growth of a plant, and has a cultivation surface on the boundary with the plant to be cultivated, holds the plant to be cultivated and supplies at least moisture. A light source that emits light, a scanning unit that directs the light emitted from the light source to at least one of the cultivation target plant or the cultivation tank, and at least one of the cultivation target plant or the cultivation tank A light receiving unit that receives the reflected light, and a control unit that changes a light amount of the light source based on a light receiving state of the light receiving unit, the control unit is irradiated with light from the scanning unit to a plant to be cultivated The light amount of the light source is increased when it is determined that the light is emitted, and the light amount of the light source is decreased when it is determined that the light from the scanning unit is irradiated on the cultivation surface of the cultivation tank. Thus, the light receiving unit receives both the light reflected from the plant to be cultivated and the light reflected from the cultivation surface of the cultivation tank, and is reflected from the light reflected from the plant to be cultivated and the cultivation surface of the cultivation tank. Can be distinguished from light. Furthermore, when it is determined that the light from the scanning unit is irradiated on the plant to be cultivated, the light amount of the light source is increased, and when it is determined that the light from the scanning unit is irradiated on the cultivation surface of the cultivation tank Since the light amount of the light source is reduced, the light amount is changed depending on whether the light from the light source contributes to the growth of the plant or not, and the light use efficiency of the light source when growing the plant is increased. be able to.

  In the invention according to claim 2, the light receiving unit has a function of detecting the amount of light reflected from at least one of the cultivation target plant or the cultivation tank, and the amount of light received by the light receiving unit is predetermined. It is determined that the light is reflected from the cultivation surface of the cultivation tank when the light amount is exceeded, and is determined to be the light reflected from the plant to be cultivated when the light amount received by the light receiving unit does not exceed the predetermined light amount. Features. Thereby, a plant and other cultivation surfaces can be detected at a low cost by using a light receiving element that measures the amount of light irradiated for plant cultivation and the amount of reflected light from the irradiation object.

  In the invention according to claim 3, the light source unit emits light in a pulsed state, and the light receiving unit detects light reflected from at least one of the plant to be cultivated or the cultivation surface of the cultivation tank, and the irradiated light. It has a function to measure the distance to the cultivation surface of the plant to be cultivated or the cultivation tank from the difference in the time axis of the reflected light, and light from the cultivation surface of the cultivation tank when the measured distance exceeds a predetermined distance If the measured distance does not exceed a predetermined distance, it is determined that the plant is a plant to be cultivated. This makes it possible to detect plants and other cultivation surfaces at a low cost by using a light receiving element that measures the distance from the difference between the time axis of the light irradiated for plant cultivation and the reflected light from the irradiation object. be able to.

In the invention according to claim 4, the control unit has a function of adjusting the light receiving sensitivity of the light receiving unit,
The light receiving sensitivity of the light receiving unit is lowered when the light amount of the light source is increased, and the light receiving sensitivity of the light receiving unit is increased when the light amount of the light source is reduced. As a result, in the control unit that changes the light amount of the light source in order to increase the light utilization efficiency, it is possible to avoid saturation of the light receiving unit by changing the light receiving sensitivity of the light receiving unit according to the light amount of light. The amount of light can be measured.

  Invention of Claim 5 is a plant cultivation apparatus which promotes the growth of a plant, has a cultivation surface on a boundary with a plant to be cultivated, holds a plant to be cultivated and supplies at least moisture A light source that emits light, a scanning unit that directs the light emitted from the light source to at least one of the cultivation target plant or the cultivation tank, and at least one of the cultivation target plant or the cultivation tank A light receiving unit that receives the reflected light, a reflector that is located on the cultivation surface of the cultivation tank and reflects light from the scanning unit, and a control unit that determines a scanning range of the scanning unit based on a light receiving state of the light receiving unit; Is provided. Thus, the light receiving unit receives both the light reflected from the plant to be cultivated and the light reflected from the cultivation surface of the cultivation tank, and is reflected from the light reflected from the plant to be cultivated and the cultivation surface of the cultivation tank. Can be distinguished from light. Furthermore, even when the plant to be cultivated grows, the control unit can accurately grasp the size of the plant to be cultivated.

  The invention according to claim 6 is characterized in that the light from the light source is light of the first wavelength, and the reflector converts the light of the first wavelength into light of the second wavelength different from the first wavelength. . Thereby, since a reflector converts the light of the 1st wavelength from a light source into the 2nd wavelength different from the light of the 1st wavelength, the wavelength of the light reflected from a cultivation object and the light reflected from a reflector is different. The light reflected from the plant to be cultivated and the light reflected from the cultivation surface of the cultivation tank can be easily distinguished.

  The invention according to claim 7 is characterized in that the first wavelength light is blue light (wavelength: 400 to 500 nm) and the second wavelength light is red light (wavelength: 600 to 700 nm). And Thus, the first wavelength light from the light source is blue light, the second wavelength light different from the first wavelength from the reflector is red light, and the first wavelength light and the second wavelength light are plant light. Since the wavelength is suitable for photosynthesis, the light reflected from the plant to be cultivated and the light reflected from the cultivation surface of the cultivation tank can be easily distinguished and photosynthesis of the plant can be promoted.

  The invention according to claim 8 is characterized in that the control unit changes the scanning range of the scanning unit so as to irradiate the plant to be cultivated with light from the light source based on the light reception state of the light receiving unit. Thereby, the control unit changes the scanning range of the scanning unit so as to mainly irradiate the plant to be cultivated with light from the light source, so the ratio of irradiating the cultivation surface of the cultivation tank with light from the light source is reduced. And since the ratio irradiated to the plant of cultivation object is increased, the utilization efficiency of the light of the light source at the time of growing a plant can be improved.

  In the invention according to claim 9, the light receiving unit has a function of detecting the amount of light reflected from at least one of the plant to be cultivated or the cultivation surface of the cultivation tank, and the amount of light received by the light receiving unit is predetermined. It is determined that the light is reflected from the cultivation surface of the cultivation tank when the light amount is exceeded, and is determined to be the light reflected from the plant to be cultivated when the light amount received by the light receiving unit does not exceed the predetermined light amount. Features. Thereby, a plant and other cultivation surfaces can be detected at a low cost by using a light receiving element that measures the amount of light irradiated for plant cultivation and the amount of reflected light from the irradiation object.

  In the invention according to claim 10, the light source unit emits light in a pulsed state, and the light receiving unit detects light reflected from at least one of the cultivation surface of the plant to be cultivated or the cultivation tank, and the irradiated light and reflection. From the difference in the time axis of the light, it has the function of measuring the distance to the cultivation surface of the plant to be cultivated or the cultivation tank, and the light from the cultivation surface of the cultivation tank when the measured distance exceeds a predetermined distance Judgment is made, and when the measured distance does not exceed a predetermined distance, it is judged as a plant to be cultivated. This makes it possible to detect plants and other cultivation surfaces at a low cost by using a light receiving element that measures the distance from the difference between the time axis of the light irradiated for plant cultivation and the reflected light from the irradiation object. be able to.

  According to an eleventh aspect of the present invention, the light from the light source is divergent light, and has a collimator lens that converts the light from the light source into parallel light. Thereby, when detecting a plant by optically converting divergent light into parallel light and narrowing the light, it is possible to accurately detect a boundary portion such as an edge of the plant.

(Embodiment 1)
Hereinafter, the plant cultivation apparatus in Embodiment 1 of this invention is demonstrated, referring drawings.

  FIG. 1 is a perspective view showing a plant cultivation apparatus.

A plant cultivation apparatus 1 shown in the figure is a fully-controlled plant cultivation apparatus 1 that uses artificial lighting configured to grow plants. The plant cultivation apparatus 1 includes a light source unit 2, a light receiving unit 3, a cultivation tank 4, and a control unit 6 (not shown).
As for the plant 5 to be cultivated, there are leafy vegetables such as lettuce and red cabbage, which are generally said to be easy to grow with artificial light, and tomatoes which are fruit seeds and a kind of green-yellow vegetables. In recent years, cereals such as rice have been studied for cultivation in plant factories.

  The cultivation tank 4 is filled with a culture solution for growing the plant 5 (both hydroponics and soil cultivation), and the plants 5 are planted at regular intervals. The side of the planted side is called the cultivation surface 7.

  The control unit 6 includes a light emitting circuit for emitting light from the semiconductor laser of the light source unit 2 and a light receiving circuit for controlling the operation of the light receiving element of the light receiving unit 3, and determines the amount of light emission, the irradiation timing, and the irradiation position depending on the light reception state. It has a function to control.

  FIG. 2 is a diagram illustrating an internal configuration of the light source unit.

  The light source unit 2 includes a light source 21 and a scanning unit 31. The light source 21 emits blue light (hereinafter referred to as “first semiconductor laser 22”) and a semiconductor laser that emits red light. (Hereinafter, “second semiconductor laser 23”) is accommodated. Next, an optical prism 24 for making the light emitted from the first semiconductor laser 22 and the second semiconductor laser 23 into one optical path is provided, and the light emitted from the semiconductor laser is diverged light. A collimator lens 25 that converges the divergent light into parallel light is provided. The amount of light emitted from the first semiconductor laser 22 and the second semiconductor laser 23 is obtained by dispersing light of a predetermined ratio of the light emitted by the film characteristics of the optical prism 24 and optically arranged on the side surface of the optical prism 24. The light amount can be measured by the monitor 26 and can be maintained at the light amount instructed by the control unit 6.

  The first wavelength of the light emitted from the first semiconductor laser 22 is in the range of 400 to 500 nm, the second wavelength of the light emitted from the second semiconductor laser 23 is in the range of 600 to 700 nm, A wavelength that most efficiently promotes photosynthesis of the plant 5 is used.

  FIG. 3 is a diagram illustrating a configuration of a scanning unit included in the light source unit.

  The scanning unit 31 includes a movable plate 32, a beam 33, and a coil 34 formed of a single crystal silicon substrate 37. Further, on the surface of the movable plate 32, a reflection mirror 35 for irradiating the plant 5 with emitted light, A coil 34 is formed. In addition, a permanent magnet 36 is disposed on the peripheral edge of the single crystal silicon substrate 37, and a magnetic circuit is configured together with the coil 34. When a current is passed through the coil 34 formed on the outer peripheral portion of the movable plate 32, Lorentz force is generated by the interaction with the magnetic field by the permanent magnet 36. As a result, the movable plate 32 can be tilted to an angle balanced with the restoring force of the beam 33, and the reflecting mirror 35 is tilted at the same time. Since the Lorentz force is proportional to the current flowing through the coil 34, the inclination of the movable plate 32, that is, the angle of optical scanning, can be freely changed within the rated range by changing its value. By providing the function of operating this movement in two axes, the emitted light emitted from the light source 21 can be scanned two-dimensionally.

  As a method of detecting the angle of the reflection mirror 35 that determines the range of the optical scanning, a method of detecting a counter electromotive force generated in the coil 34 that swings in a magnetic field. A method in which a beam 33 is provided with a piezoresistive element, and a change in the resistance value of the piezoresistive element is electrically detected from the stress of the beam 33 generated by rocking. There is a method in which light reflected from the reflection mirror 35 is detected by an optical sensor, and a deflection angle is detected from the passage time of the reflected light.

  Further, as a method of tilting the reflection mirror 35, there is a method using a piezoelectric element or an electrostatic force in addition to the method using the magnetic circuit described above.

  FIG. 4 is a diagram illustrating a configuration of the light receiving unit.

  The light receiving unit 3 includes a light receiving element 41 that detects the amount of light and a condenser lens 42. The light reflected from at least one of the plant 5 to be cultivated or the cultivation surface 7 of the cultivation tank 4 collects the reflected light by the condenser lens 42 and is efficiently condensed on the light receiving element 41.

  FIG. 5 is a diagram illustrating an integrated configuration of the light source unit and the light receiving unit.

  The light source 21 houses a first semiconductor laser 22 that emits blue light and a second semiconductor laser 23 that emits red light. Next, an optical prism 24 for making the light emitted from the first semiconductor laser 22 and the second semiconductor laser 23 into one optical path is provided, and the light emitted from the semiconductor laser is diverged light. A collimator lens 25 that converges the divergent light into parallel light is provided. The amount of light emitted from the first semiconductor laser 22 and the second semiconductor laser 23 is obtained by dispersing light of a predetermined ratio of the light emitted by the film characteristics of the optical prism 24 and optically arranged on the side surface of the optical prism 24. The light amount can be measured by the monitor 26 and can be maintained at the light amount instructed by the control unit 6. A half mirror 43 is provided between the collimator lens 25 and the scanning unit 31, the emitted light of the semiconductor laser is transmitted, and the return light reflected from at least one of the cultivation target plant 5 or the cultivation surface 7 of the cultivation tank 4 is reflected. A reflection film is provided and is directed to the light receiving element 41 provided on the half mirror 43 side.

  The light source unit 2 and the light receiving unit 3 can be separately disposed, and at the same time, can be configured in a compact and integrated manner using the half mirror 43 as described above.

  FIG. 6 is a diagram illustrating a method of detecting the light amount of the plant and the cultivation surface of the cultivation tank.

  The light emitted from the light source unit 2 is blue light emitted from the first semiconductor laser 22 or red light emitted from the second semiconductor laser 23, and is applied to the plant 5 to be cultivated or the cultivation surface 7 of the cultivation tank 4. Is irradiated.

  The light receiving unit 3 has a function of detecting the amount of light reflected from at least one of the plant 5 or the cultivation surface 7.

  The control unit 6 performs light emission control of the light emitting circuit 61 that emits the semiconductor laser, determines the light emission amount and irradiation position of the light emitted from the light source unit 2, and also performs light reception control of the light receiving circuit 62 that operates the light receiving element 41. The light receiving sensitivity of the light receiving unit 3 is also adjusted. For this reason, the control unit 6 can adjust the amount of light emitted from the light source unit 2 based on the amount of light received by the light receiving unit 3.

  With respect to the irradiation position, it is based on information such as an optical sensor or a piezoresistive element that measures the tilt amount of the reflection mirror 35 of the scanning unit 31 provided in the light source unit 2, or back electromotive force generated when the reflection mirror 35 is tilted. The irradiation position of the light emitted from the light emitting circuit 61 can be grasped. At the same time, the position of the received light can be grasped through the light receiving circuit 62.

  Here, since the plant 5 absorbs blue light and red light that promote photosynthesis, the amount of light reflected from the plant 5 is smaller than the amount of light reflected from the cultivation surface 7 other than the plant 5. Therefore, the control part 6 can judge that it is the light reflected from the cultivation surface 7 of the cultivation tank 4 when the light quantity of the light received by the light receiving part exceeds a predetermined light quantity, and the light quantity of the light received by the light receiving part is the predetermined light quantity. Can be determined as light reflected from the plant 5 to be cultivated.

  Moreover, since the cultivation surface 7 of the cultivation tank 4 can return a large amount of light to the light receiving unit 3 by including the reflector 63, the plant 5 and the cultivation tank 4 return from the cultivation surface 7. Light contrast (light quantity difference) can be increased.

  Furthermore, the wavelength of the light irradiated to the cultivation surface 7 of the cultivation tank 4 can be converted and returned to the light receiving unit 3 by using a phosphor that can convert the wavelength of the light instead of the reflector 63. . When a phosphor that converts this wavelength is used, it is possible to easily specify where the light received by the light receiving element 41 is returned by attaching a wavelength selection filter to the light receiving element 41.

  FIG. 7 is a diagram illustrating a method for detecting a distance between a plant and a cultivation surface of a cultivation tank. The light emitted from the light source unit 2 is light in a pulse state, and is irradiated to the plant 5 or the cultivation surface 7 of the cultivation tank 4. The light receiving unit 3 detects the light reflected from at least one of the cultivation target plant 5 or the cultivation surface 7 of the cultivation tank 4, and the distance measurement circuit 64 determines the difference between the time axis of the irradiated light and the reflected light, It has the function of measuring the distance to the cultivation surface 7 of the plant 5 or the cultivation tank 4 to be cultivated.

  Therefore, the control part 6 judges that it is the light from the cultivation surface 7 of the cultivation tank 4 when the measured distance exceeds a predetermined distance, and judges that it is the plant 5 to be cultivated when the measured distance does not exceed the predetermined distance. To do.

  With respect to the irradiation position, it is based on information such as an optical sensor or a piezoresistive element that measures the tilt amount of the reflection mirror 35 of the scanning unit 31 provided in the light source unit 2, or back electromotive force generated when the reflection mirror 35 is tilted. The irradiation position of the light emitted from the light emitting circuit 61 can be grasped. At the same time, the position of the cultivation surface 7 of the plant 5 or the cultivation tank 4 from which the distance has been measured can be grasped via the distance measurement circuit 64.

  FIG. 8 is a diagram showing an irradiation state of the plant cultivation apparatus, and shows a state of the first example.

  6 and 7, the control unit 6 can determine the plant 5 and the cultivation surface 7 of the cultivation tank 4. As a result, when it is determined that the light from the scanning unit 31 is irradiated on the plant 5 to be cultivated, the light amount of the light source 21 is increased to a predetermined light amount necessary for the photosynthesis of the plant 5, and the light from the scanning unit 31 is increased. When it is determined that the cultivation surface 7 of the cultivation tank 4 is irradiated, the light amount of the light source 21 is reduced. In FIG. 8, the portion indicated by a thick solid line is a predetermined light amount (high light amount) necessary for photosynthesis, and the portion indicated by a broken line indicates a minimum light amount (low light amount) that can detect return light. .

  As shown in FIG. 8, it is possible to detect the plant 5 and switch the irradiation light in real time while scanning the irradiation light. Further, in the case of real-time operation, when the amount of light in the scanning direction of irradiation light is viewed macroscopically, for example, if the next irradiation applied to the cultivation surface 7 with a small amount of light is performed on the time axis, the amount of light is small. There is a possibility of being irradiated in the state. In that case, the control unit 6 has a function of performing correction based on the previous scanning position information of the plant 5 and the cultivation surface 7 in the next irradiation cycle.

  Further, the control unit 6 has a function of adjusting the light receiving sensitivity of the light receiving unit 3. When the light amount of the light source 21 is increased, the light receiving sensitivity of the light receiving unit 3 is decreased and when the light amount of the light source 21 is decreased. In addition, the light receiving sensitivity of the light receiving unit 3 can be increased, and saturation of the light receiving element 41 provided in the light receiving unit 3 can be avoided.

  FIG. 9 is a diagram showing an irradiation state of the plant cultivation apparatus, and shows a second example state.

  First, the plant 5 and the cultivation surface 7 of the cultivation tank 4 are irradiated with a fixed amount of light, and the control unit 6 uses the method described in FIGS. Judging. In the left figure of FIG. 9, the part shown with the broken line has shown the area | region irradiated with the fixed light quantity. From the result, the positional information of the plant 5 and the cultivation surface 7 of the cultivation tank 4 is taken in, and the scanning range is determined. This operation is hereinafter referred to as mapping search. After the next irradiation cycle, the control unit 6 irradiates only the predetermined light amount necessary for the photosynthesis of the plant 5 by limiting to the scanning range of the plant 5, and the light amount is zero for the cultivation surface 7 of the cultivation tank 4. Do not irradiate. In the right diagram of FIG. 9, a portion indicated by a thick solid line is a predetermined light amount (high light amount) necessary for photosynthesis, and the other regions have zero light amount. The operation ratio between the mapping search and the limited irradiation of only the plant 5 can be freely changed.

  Further, the irradiation method using the real-time operation in the first example described above with reference to FIG. 8 and the irradiation method limited to the plant 5 only after the mapping search in the second example may be performed in combination with different ratios.

  The present invention can improve the light utilization efficiency at a low cost, and therefore can be applied to a plant cultivation apparatus for cultivating plants by artificial lighting.

DESCRIPTION OF SYMBOLS 1 Plant cultivation apparatus 2 Light source part 3 Light receiving part 4 Cultivation tank 5 Plant 6 Control part 7 Cultivation surface 21 Light source 22 1st semiconductor laser 23 2nd semiconductor laser 24 Optical prism 25 Collimator lens 26 Optical monitor 31 Scanning part 32 Movable plate 33 Beam 34 Coil 35 Reflecting mirror 36 Permanent magnet 37 Single crystal silicon substrate 41 Light receiving element 42 Condensing lens 43 Half mirror 61 Light emitting circuit 62 Light receiving circuit 63 Reflector 64 Distance measuring circuit

Claims (11)

A plant cultivation device that promotes plant growth,
A cultivation tank having a cultivation surface on the boundary with the plant to be cultivated, holding the plant to be cultivated and supplying at least moisture,
A light source that emits light;
A scanning unit for directing light emitted from the light source to at least one of the cultivation target plant or the cultivation tank;
A light receiving portion that receives light reflected from at least one of the cultivation target plant or the cultivation surface of the cultivation tank; and
A control unit that changes a light amount of the light source based on a light receiving state of the light receiving unit,
The controller is
Increasing the amount of light of the light source when it is determined that the light from the scanning unit is irradiated on the plant to be cultivated,
The plant cultivation apparatus, wherein the light amount of the light source is reduced when it is determined that the light from the scanning unit is irradiated on the cultivation surface of the cultivation tank. The light receiving unit is
Having a function of detecting the amount of light reflected from at least one of the cultivation target plant or the cultivation tank;
When the amount of light received by the light receiving unit exceeds a predetermined amount of light, it is determined as light reflected from the cultivation surface of the cultivation tank,
The plant cultivation apparatus according to claim 1, wherein when the amount of light received by the light receiving unit does not exceed the predetermined amount of light, the light is reflected from the plant to be cultivated. The light source is
Irradiate pulsed light,
The light receiving unit is
The light reflected from at least one of the plant to be cultivated or the cultivation surface of the cultivation tank is detected, and from the time axis difference between the irradiated light and the reflected light, the plant to be cultivated or the cultivation surface of the cultivation tank Has a function to measure the distance to
When the measured distance exceeds a predetermined distance, it is determined as light from the cultivation surface of the cultivation tank,
The plant cultivation apparatus according to claim 1, wherein when the measured distance does not exceed a predetermined distance, the plant is determined as the plant to be cultivated. The controller is
Having a function of adjusting the light receiving sensitivity of the light receiving unit;
When the light quantity of the light source is increased, the light receiving sensitivity of the light receiving unit is lowered,
The plant cultivation apparatus according to claim 1, wherein when the light amount of the light source is reduced, the light receiving sensitivity of the light receiving unit is increased. A plant cultivation device that promotes plant growth,
A cultivation tank having a cultivation surface on the boundary with the plant to be cultivated, holding the plant to be cultivated and supplying at least moisture,
A light source that emits light;
A scanning unit for directing light emitted from the light source to at least one of the cultivation target plant or the cultivation tank;
A light receiving portion that receives light reflected from at least one of the cultivation target plant or the cultivation surface of the cultivation tank; and
A reflector that is located on the cultivation surface of the cultivation tank and reflects light from the scanning unit;
A plant cultivation device comprising: a control unit that determines a scanning range of the scanning unit based on a light reception state of the light receiving unit. The light from the light source is light of the first wavelength,
6. The plant cultivation apparatus according to claim 5, wherein the reflector converts the light having the first wavelength into light having a second wavelength different from the first wavelength. The first wavelength light is blue light (wavelength: in the range of 400 to 500 nm),
The plant cultivation apparatus according to claim 6, wherein the second wavelength light is red light (wavelength: in a range of 600 to 700 nm). The controller is
The plant cultivation apparatus according to claim 5, wherein the scanning range of the scanning unit is changed so as to irradiate the plant to be cultivated with light from the light source based on a light reception state of the light receiving unit. The light receiving unit is
Having a function of detecting the amount of light reflected from at least one of the cultivation target plant or the cultivation tank;
When the amount of light received by the light receiving unit exceeds a predetermined amount of light, it is determined as light reflected from the cultivation surface of the cultivation tank,
The plant cultivation apparatus according to claim 5, wherein when the amount of light received by the light receiving unit does not exceed the predetermined light amount, the light is reflected from the plant to be cultivated. The light source is
Irradiate pulsed light,
The light receiving unit is
The light reflected from at least one of the plant to be cultivated or the cultivation surface of the cultivation tank is detected, and from the time axis difference between the irradiated light and the reflected light, the plant to be cultivated or the cultivation surface of the cultivation tank Has a function to measure the distance to
When the measured distance exceeds a predetermined distance, it is determined as light from the cultivation surface of the cultivation tank,
The plant cultivation apparatus according to claim 5, wherein the plant is determined to be a plant to be cultivated when the measured distance does not exceed a predetermined distance. The light from the light source is divergent light,
The plant cultivation apparatus according to claim 5, further comprising a collimator lens that converts light from the light source into parallel light.

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