JP5463470B2 - Light amount control device and light irradiation device - Google Patents

Description

  The present invention relates to a light amount control device that controls the amount of light emitted from an LED to a predetermined irradiation area, and a light irradiation device in which an LED is connected to the light amount control device. ), Which is preferably used for inspection such as the presence or absence of scratches and the reading of marks.

  Conventionally, in-line high-speed inspection of WEB (continuous material: for example, film, paper, metal plate, etc.) and BATCH (single-sheet product, individual product: for example, cut film, cut glass, drum, etc.) which are inspection objects When using a line sensor camera, the surface of the flowing workpiece is continuously captured as image information one after another, and surface defects are detected by detecting parts of different brightness in the image information processing device. I have to. As a lighting device (light irradiation device) used at that time, a device in which a plurality of LEDs excellent in responsiveness, luminous stability, life and the like are arranged in a row has been developed.

  By the way, in order to detect surface defects with high accuracy, it is necessary to uniformly illuminate the imaging target area by the camera with a uniform and constant light intensity. Especially in a light irradiation device used in a line sensor, a light irradiation surface There is also a demand for a variation in the amount of light at a few percent or less. In response to such a requirement, in the light irradiation device using the LED, even if the LEDs are arranged adjacent to each other, variation in the amount of light occurs in the column direction due to the discontinuity. Difficult to meet demand.

  Because even if each LED is of the same standard, it has an error in manufacturing, and even if constant current control of each LED is performed with the same current value, the actual light quantity emitted from each LED is reduced. This is because there is a difference, and as a result, the amount of light varies in the entire irradiation region.

  On the other hand, a method of selecting an LED to suppress variation in the actual light amount is conceivable. However, in this type of light irradiation apparatus that requires several hundreds of LEDs in some cases, the cost and the manufacturing can be reduced. The amount of effort will be enormous.

  In addition, for example, it may be possible to independently control the light amount of each LED using an illuminance sensor or the like. However, the configuration is complicated, and it is difficult to control due to the influence of light from other LEDs in the vicinity. There is. In particular, when several hundreds of LEDs are used as described above, the problem becomes extremely remarkable.

  In order to solve such a problem, for each LED or LED group, the irradiated light is measured by a sensor, and the actual light quantity value measured and the LED or LED group from the power supply unit in order to obtain the actual light quantity value An actual light quantity value-current value table, which is a table showing the relationship between the current value that needs to be supplied to the current value, is created in advance.

  More specifically, in the light irradiation device described in Patent Document 1, the light amount command value input to the light amount command value receiving unit with reference to the actual light amount value-current value table for each LED or LED group described above. A real light value matching or close to the real light value is retrieved, and a current value corresponding to the actual light value is obtained for each LED or LED group. And it is set as illumination without the light quantity nonuniformity as a whole by applying separately the electric current value acquired for every LED or LED group, respectively.

  In other words, by referring to the table, with respect to one input light quantity command value, separate current values to be applied for each LED or LED group are acquired from a previously created table, and those current values are applied. In this way, a customized current value can be applied according to the variation of each LED or LED group, and as a result, the entire light amount can be made uniform with the light amount command value.

  By the way, such a method works well when the unit dimensions of the light quantity command value and the actual light quantity value coincide with each other in lux or the like. It is difficult to use the range when it is used such as when it is desired to always control the light quantity with the same resolution. More specifically, each time the inspection object changes, the actual light quantity range that can be emitted from the LED or LED group can be appropriately changed to a real light quantity range that is particularly suitable for the inspection object, and within the changed range. Therefore, it is difficult to perform light quantity control with the same number of gradations in the light irradiation apparatus as described above.

JP 2003-269919 A

  The present invention has been made in view of the above-described problems, and in order to absorb variations in characteristics of each LED or LED group, the light amount command value and the measured actual light amount of each LED or LED group are used. It is possible to provide a light amount control device and a light irradiation device that can be adapted to each other, change the range of the actual light amount to be used as appropriate, and easily maintain the same resolution in each use range before and after the change. Objective.

  That is, the light amount control device of the present invention is a light amount control device that controls the amount of light emitted from a light emission mechanism including an LED or LED group LED group toward a predetermined irradiation region, and includes a supply current value and a supply voltage value. Receiving a driving parameter such as an ON / OFF ratio in pulse driving as an input, and outputting a power determined by the driving parameter to the light emitting mechanism; a predetermined number of gradations; A light amount command value receiving unit that receives a light amount command value indicating a degree, and a drive parameter that is input to the power supply unit in a state where it is measured that a desired actual light amount is irradiated from the light emission mechanism; A correspondence storage unit that stores a plurality of correspondence data paired with a light quantity command value, a light quantity command value received by the light quantity command value reception unit, and a plurality of correspondence relations And a light amount command value conversion unit that converts the light amount command value received by the light amount command value reception unit into a drive parameter corresponding to the light amount command value and inputs the drive parameter to the power supply unit. A drive parameter forced input unit for forcibly inputting a desired drive parameter to the power supply unit, and the light quantity command value receiving unit when a drive parameter is forcibly input from the drive parameter forced input unit. The correspondence data is created by pairing the light quantity command value accepted by the drive parameter and the drive parameter input to the power supply unit by the drive parameter forced input unit, and a new correspondence is created in the correspondence storage unit. And a correspondence data creating unit for storing the data as relation data.

  If it is such, in the state which input the light quantity command value which wants to match | combine with a desired real light quantity to the said light quantity command value reception part, desired real light quantity is irradiated from the said light irradiation apparatus by the said drive parameter forced input part. As described above, by changing the drive parameter, it is possible to associate a drive parameter capable of realizing an arbitrary actual light quantity with each light quantity command value.

  Furthermore, since the light quantity command value received by the light quantity command value receiving unit has the number of gradations, for example, with respect to the light quantity command values having two different gradation numbers, respectively, the desired two actual light quantities are obtained. By associating the corresponding drive parameters, it is possible to easily correspond to the actual light amount without changing the resolution within the use range.

  Therefore, even when the inspection target is changed, the current light amount received by the light amount command value receiving unit is simply changed to the actual light amount irradiated from the LED or LED group by the drive parameter forced input unit. A new drive parameter for realizing a desired actual light quantity can be associated with the command value. Therefore, the correspondence data in which the light amount command value and the drive parameter are paired can be updated and the number of gradations of the light amount command value can be updated only by appropriately changing the actual light amount at the drive parameter forced input unit. Since there is no change, the amount of light can be controlled with the same resolution even if the use range of the actual amount of light emitted from the light emission mechanism is changed.

  As a specific embodiment for obtaining the effect as described above, the correspondence data generation unit changes the drive parameter input to the power supply unit by the drive parameter forced input unit, and the light When a desired actual light amount is irradiated from the emission mechanism, the drive parameter input to the power supply unit can be associated with a light amount command value having an arbitrary gradation value. That's fine.

  It is easy to associate a drive parameter for realizing an arbitrary actual light amount with a light amount command value, and in order to simplify the configuration for that purpose, a desired actual light amount is emitted from an LED or a group of LEDs. A timing signal generator for generating a timing signal when the correspondence data creation unit detects the timing signal, and stores the new correspondence data in the correspondence storage unit Anything is acceptable.

  Even when the drive parameter forced input unit changes the drive parameter to realize the desired actual light amount associated with the light amount command value, and the usage range of the actual light amount irradiated from the light emission mechanism is changed, the same light amount command value is always obtained As a specific embodiment for enabling the actual light amount to be changed with the resolution of the first light amount command value, the light amount command value conversion unit includes a first light amount command value having a first gradation and the first light amount command value. A first drive relationship data paired with a first drive parameter corresponding to the second light quantity command value having the second gradation, a second drive parameter corresponding to the second light quantity command value, A linear function indicating the correspondence between the gradation value of the light amount command value and the drive parameter is calculated based on the second correspondence relationship data paired with each other, and the light amount command value receiving unit is calculated based on the linear function. Accepted light It calculates a drive parameter corresponding to the command value, as long as it is configured to enter into the power supply unit.

  In order to make it easy to determine which range of the actual light quantity that can be emitted from the light emission mechanism is to be used, and to easily understand the correspondence with the light quantity command value, the first light quantity command value May have the smallest gradation value, and the second light quantity command value may have the largest gradation value.

  In the actual light intensity range that is often used, it is possible to control with fine resolution, and in the other actual light intensity usage range, the actual light intensity can be changed greatly by changing the light intensity command value slightly. In order to be able to optimize the amount of change in the actual light amount with respect to the change in the light amount command value for each use range, the correspondence relationship storage unit includes the first correspondence relationship data, the second correspondence relationship data, and the third correspondence relationship. The light quantity command value of each correspondence data has a relationship that increases in the order of the first light quantity command value, the second light quantity command value, and the third light quantity command value. The value conversion unit indicates the correspondence between the gradation value of the light quantity command value between the first light quantity command value and the second light quantity command value and the drive parameter based on the first correspondence relation data and the second correspondence relation data. 1 linear function The second linear function indicating the correspondence between the gradation value of the light quantity command value between the second light quantity command value and the third light quantity command value and the drive parameter based on the second correspondence relation data and the third correspondence relation data. When the light quantity command value received by the light quantity command value receiving unit is between the first light quantity command value and the second light quantity command value, the drive parameter is calculated based on the first linear function. When the light quantity command value received by the light quantity command value receiving unit is between the second light quantity command value and the third light quantity command value, the drive parameter is calculated based on the second linear function. Anything can be used.

  Even if the characteristics of the LED change due to changes over time or temperature, it is possible to automatically realize the desired actual light quantity without resetting the correspondence between the light quantity command value and the drive parameter, and the light quantity control is almost the same as at the time of setting. In order to maintain the feeling of use, the apparatus further includes a light amount measuring unit that measures the actual light amount in the predetermined irradiation region, and the correspondence storage unit stores the associated light amount command value and the drive parameter. At the same time, the actual light quantity at the time of setting measured by the light quantity measurement unit at the time of association is stored, and the light quantity command value conversion part converts the light quantity command value received by the light quantity command value reception part. When there is a deviation between the actual light quantity at normal control measured by the light quantity measuring unit and the actual light quantity at the time of setting, the drive parameter converted from the light quantity command value based on the deviation is set. As long as it is configured to forward to.

  In order to achieve a desired actual light amount effectively with a single feedback loop without forming a plurality of feedback loops, the light amount measurement unit is configured to brightness the image captured in the predetermined irradiation region. As long as it is configured to measure the actual light quantity based on the above.

  If the light irradiation device includes the light amount control device described above and the light emission mechanism, even if a light emission mechanism having different characteristics is connected to the light amount control device, it is possible to select any light by simply inputting the same light amount command value. A desired actual light quantity can also be obtained by the injection mechanism.

  As described above, in the light amount control device and the light irradiation device of the present invention, the drive parameter capable of realizing the actual light amount is divided into the necessary portions of the actual light amount that can be irradiated by the light emission mechanism, and the drive parameter that can realize the actual light amount is used as the light amount command value. While being able to associate, the use range can be suitably changed by a drive parameter forced input part. Moreover, even if the use range becomes wider or narrower before and after the change, for example, the use range can be divided by the number of gradations of the light quantity command value, and the light quantity control can always be performed with the same resolution.

The schematic diagram which shows the light irradiation apparatus which concerns on one Embodiment of this invention. The typical perspective view which shows the detail of the light emission mechanism in the embodiment. The schematic diagram which shows the external appearance of the light quantity control apparatus in the embodiment. The schematic diagram which shows the internal structure of the light quantity control apparatus in the embodiment. The functional block diagram at the time of the normal control mode in the same embodiment. The functional block diagram at the time of the setting mode in the embodiment. An example of correspondence data stored in the correspondence storage unit in the embodiment. The typical graph which shows the relationship between the actual light quantity at the time of the initial setting in the same embodiment, an applied electric current value, and a light quantity command value. The typical graph which shows the relationship between the real light quantity at the time of use range change in the same embodiment, an applied electric current value, and a light quantity command value. The typical graph which shows the relationship between the real light quantity in another embodiment of this invention, an applied electric current value, and a light quantity command value. The typical graph which shows the relationship between the real light quantity in another implementation meter etc. of this invention, an applied electric current value, and a light quantity command value.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 schematically shows an overall outline of a product inspection system using a light irradiation apparatus 1 according to the present embodiment. The inspection object (work) W in the figure is a continuous object such as translucent paper or film, and is set to flow at a constant speed in a predetermined direction. The light irradiation device 1 according to the present embodiment irradiates the predetermined irradiation area AR of the inspection object (work) W with line-shaped light, and the imaging apparatus CMR called a line sensor camera uses the predetermined irradiation area. The AR is photographed, and the obtained image data is captured by an image processing apparatus (not shown) to perform an automatic surface inspection for the presence or absence of scratches.

  As shown in the figure, the light irradiation device 1 includes a plurality of light emission mechanisms 2 that can independently adjust the light amount, and light amounts that are connected to the light emission mechanism 2 by an electric cable CA and drive and control them. And a control device 3.

  As shown in FIG. 2, the light emission mechanism 2 is a single ultra-high brightness type LED 4 (so-called power LED, which can continuously flow a current of 200 mA or more. LED 4 is not shown and is housed inside LED housing 21), a large number of optical fibers 22 connected to LED 4 with light introduction ends, and the light output ends of each optical fiber 22 face each other. And a pair of holding members 23 that are sandwiched from the direction to be held tightly in one row. These light emission mechanisms 2 are held by a common support 24 so as to be arranged in a row, and in this state, the holding members 23 are adjacent to each other, and the light output ends of all the optical fibers 22 are linear in a row. And are arranged so as to be arranged almost densely.

  As shown in FIG. 4, the light quantity control device 3 includes a main board 31 having a CPU, a memory, an I / O interface, a communication interface, and the like, a plurality of drive boards 32 provided corresponding to the respective LEDs 4, and The casing 33 accommodates the boards 31 and 32, and a switch, a volume, a connector, and the like attached to the casing 33. The drive board 32 includes, for example, a latch circuit, a D / A converter, a current output circuit, and the like. Then, the CPU and other units cooperate in accordance with a program set in the predetermined area of the memory, so that a mode switching unit 301, a power supply unit 307, a light quantity command value receiving unit are provided as shown in FIGS. 302, the correspondence relationship storage unit 304, the light intensity command value conversion unit 303, the drive parameter forced input unit 305, and the correspondence relationship data creation unit 306 are exhibited.

  The light irradiation apparatus 1 according to the present embodiment varies the form of light quantity control between a case where normal light quantity control is performed as described later and a case where a light quantity command value and a drive parameter are associated as preparations. As described above, the mode switching unit 301 is provided. That is, the mode switching unit 301 includes a normal control mode in which a drive parameter is input to the power supply unit 307 by the light amount command value conversion unit 303, and a drive parameter to the power supply unit 307 by the drive parameter forced input unit 305. Is switched to a setting mode in which is input. More specifically, the normal control mode is a mode in which the drive parameter is calculated from the light amount command value and the light amount irradiated from the light emitting mechanism 2 is automatically controlled, whereas the setting mode Is a control mode in which the amount of light emitted from the light emission mechanism 2 can be changed by changing to an arbitrary drive parameter regardless of the input light amount command value.

  The mode switching unit 301 is configured to determine which one of the normal control mode and the setting mode is selected by the changeover switch P1 provided in the casing 33. More specifically, when the switch is selected ON, the setting mode is selected, and when the switch is OFF, the normal control mode is selected. 5 and 6 show the operating states of the respective parts in each control mode, and those whose outer frames are indicated by dotted lines indicate that they are in a resting state.

  The power supply unit 307 receives drive parameters such as supply current, supply voltage, and ON / OFF ratio in the case of pulse driving for each LED 4, and drives the LED 4 with power determined by the drive parameter. 32 is primarily responsible for that function. In this embodiment, the LED 4 is driven at a constant current with a predetermined drive current value, and the drive parameter indicates the drive current value as a numerical value of 10 bits (0 to 1023). Further, in the power supply unit 307, the size of the number of bits and the corresponding drive current value are fixed, and these relationships cannot be changed.

  The light quantity command value receiving unit 302 receives the light quantity command value of each LED 4 as a pair with an LED identifier for identifying the LED 4 input by the LED identifying digital switch P3, and sets the light quantity command set in a predetermined area of the memory. It is stored in a value data storage unit (not shown). When the normal control mode is selected in the mode switching unit 301, the light amount command value receiving unit 302 receives the light amount command value from, for example, an external computer or reads it from an input device such as a digital switch. Or If no external connection is made, the value input by the adjustment volume P2 in FIG. 3 is accepted as the light quantity command value.

  When the setting mode is selected in the mode switching unit 301, the adjustment volume P2 is used as the driving parameter forcible input unit 305, which will be described later, to input driving parameters directly to the power supply unit 307. The value of the adjustment volume P2 is not accepted by the light quantity command value accepting unit 302 as a light quantity command value. Instead, when the MAX button P4 or the MIN button P5 constituting the timing signal generation unit described later is pressed, the light amount command value receiving unit 302 receives the maximum value or the minimum value as the light amount command value, respectively. It is configured to accept it as being done. In this embodiment, the light quantity command value has a predetermined number of gradations, and is represented by a numerical value of 8 bits (0 to 255), for example.

  The correspondence storage unit 304 includes a drive parameter and a light amount input to the power supply unit 307 in a state in which it is measured that each LED 4 of the light emitting mechanism 2 is irradiated with a desired actual light amount. A plurality of pieces of correspondence data paired with command values are stored. More specifically, for each identifier of each LED 4, the current value required to obtain a desired light amount and the light amount command value associated with the drive parameter using the forced input mode as described later. Are stored in pairs as shown in FIG. The correspondence data stored in the correspondence storage unit 304 is set to be updatable, and the correspondence between the light quantity command value and the drive parameter can be changed as appropriate. In FIG. 7, as an example, the light quantity command value has the maximum value 255 and the minimum value 0 associated with the drive parameter. However, the drive parameter may be associated with each other bit value.

  The light quantity command value conversion unit 303 operates only when the normal control mode is selected in the mode switching unit 301 as shown in FIG. 5 and is received by the light quantity command value reception unit 302. Based on the received light quantity command value and a plurality of correspondence data, the drive parameter corresponding to the light quantity command value received by the light quantity command value receiving unit 302 is converted and input to the power supply unit 307. is there. More specifically, the light amount command value conversion unit 303 includes a conversion coefficient calculation unit (not shown), a conversion coefficient storage unit, and a drive parameter calculation unit.

  The conversion coefficient calculation unit calculates a coefficient for converting the light amount command value into the drive parameter based on the two sets of correspondence data stored in the correspondence storage unit 304, and uses the coefficient as the LED identifier. And stored in the conversion coefficient storage unit. Here, the conversion coefficient calculation unit is associated when the gradation value of the light intensity command value is the maximum value and the current value associated with the gradation value of the light intensity instruction value is the minimum value. A coefficient obtained by fitting a linear function from the current value is used as a conversion coefficient. The linear function is expressed by, for example, I (α) = pα + q (I (α) is a drive parameter, α is a light quantity command value), and conversion coefficients are p and q. In this embodiment, the fitting is performed using a linear function, but the fitting may be performed using another function. In this case, the correspondence relationship data stored in the correspondence relationship storage unit 304 may be configured such that the number necessary to determine the unknown coefficient is stored.

  The drive parameter calculation unit is configured to calculate a drive parameter converted from a light amount command value for each LED 4 based on the conversion coefficient, and to input the drive parameter to the power supply unit 307. When the drive parameter is output to the power supply unit 307, the corresponding drive board 32 is identified by the LED identifier, and the drive parameter is output to the drive board 32. Each drive board 32 is provided with, for example, dip switches (not shown) set to different values. The LED identifier is compared with the value indicated by the dip switch, and the drive parameters are transmitted to the corresponding drive board 32. The

  In the following description, it is a portion that operates only when the setting mode is selected, and is a portion that functions to store the correspondence relationship data in the correspondence relationship storage unit 304.

  The drive parameter forcible input unit 305 operates only when a setting mode is selected in the mode switching unit 301, and forcibly inputs a desired drive parameter to the power supply unit 307. As described above, by turning the adjustment volume P2 in the setting mode, the power supply unit 307 can be driven with an arbitrary current value.

  The timing signal generators P4 and P5 generate a timing signal when the actual amount of light emitted from the drive parameter LED becomes a desired value. In this embodiment, the user measures the actual light amount emitted from each LED by the light amount measuring device, and presses the above-described MAX button P4 or MIN button P4 when the desired maximum value or minimum value is reached. Thus, a timing signal is generated.

  In the setting mode, the correspondence relationship data creation unit 306 includes a light amount command value received by the light amount command value reception unit 302 for each selected LED identifier when the timing signal is generated, and The correspondence parameter storage unit 304 stores the driving parameter input to the power supply unit 307 by the driving parameter forcing input unit 305 as correspondence data. In the present embodiment, as shown in the graphs of FIGS. 8 and 9, the correspondence between the light amount command value and the drive parameter in the region where the actual light amount irradiated from each LED and the applied current value maintain a linear relationship. I am trying to do it.

  An example of operation and operation of the light irradiation apparatus 1 configured as described above will be described.

  <1> Initial setting

  In this initial setting, the actual light quantity of each LED 4 is measured, and the relationship between the light quantity command value of each LED 4 and the drive parameter is set.

  The operator turns on the changeover switch to select a setting mode, and also measures the actual light amount of the LED designation digital switch P3 (LED identifier) and sets the correspondence to a desired number to be created.

  When the drive parameter forced input unit 305 recognizes that it is the setting mode, the drive parameter forced input unit 305 inputs a current value based on the value input by the adjustment volume P2 to the power supply unit 307. That is, the power supply unit 307 performs constant current control on the LED 4 corresponding to the LED identifier received by the light amount command value receiving unit 302 so that the current value is the same regardless of the light amount command value. .

  Next, the operator adjusts the actual light amount of the LED 4 by operating the light amount adjustment volume P4 so that the light amount data in the image data sent from the imaging device CMR becomes a predetermined maximum value (maximum light amount). When the maximum value is reached, the MAX button P4 is pressed. When the MAX button P4 is pressed, the light amount command value receiving unit 302 receives the maximum value (255) as the light amount command value.

  The correspondence data creating unit 306 is currently input to the power supply unit 307 by the LED identifier and the light amount command value received by the light amount command value receiving unit 302 and the drive parameter forced input unit 305. Get the current value. The correspondence relationship data creation unit 306 causes the correspondence relationship storage unit 304 to store correspondence relationship data in which the current value corresponding to the acquired maximum light intensity command value is paired with the LED identifier.

  Further, the operator operates the light amount adjustment volume P4 to adjust the actual light amount of the LED 4 so that the light amount data of the image sent from the imaging apparatus becomes a predetermined minimum value (minimum light amount), and the predetermined amount is determined in advance. When the minimum value is reached, the MIN button P4 is pressed. When the MIN button P4 is pressed, the light quantity command value receiving unit 302 receives the minimum value (0) as the light quantity command value.

  The correspondence data creating unit 306 is currently input to the power supply unit 307 by the LED identifier and the light amount command value received by the light amount command value receiving unit 302 and the drive parameter forced input unit 305. Get the current value. The correspondence relationship data creation unit 306 causes the correspondence relationship storage unit 304 to store correspondence relationship data in which the current value corresponding to the acquired minimum light intensity command value is paired with the LED identifier.

  When two sets of correspondence relationship data are stored in the correspondence relationship storage unit 304, the conversion coefficient calculation unit indicates a correspondence relationship between a light amount command value and a current value that is a drive parameter based on the correspondence relationship data. A linear function is calculated, and each coefficient representing the linear function is stored in the conversion coefficient storage unit. Specifically, the calculation procedure is as follows.

  The actual amount of light emitted from the LED 4 is a predetermined maximum amount of light Lmax, the current value applied when the MAX button P4 is pressed by the operator is Imax, and the actual amount of light emitted from the LED 4 is a predetermined minimum. The current value applied when the light amount Lmin is reached and the MIN button P4 is pressed by the operator is defined as Imin. Then, the light amount command values that are to be received by the light amount command value receiving unit 302 when each button is pressed, that is, the light amount command values for which the correspondence relationship is set are αmax and αmin, respectively.

  From these, the linear function shown in Formula 1 is calculated (see FIG. 8), and the coefficient portion is stored in the conversion coefficient storage unit.

  Formula 1 I (α) = ((Imax−Imin) / (αmax−αmin)) α + (Imax · αmin−Imin · αmax) / (αmax−αmin)

  <2> Light emission operation

  In order to irradiate light from each LED 4, first, the operator sets the changeover switch to the OFF side. Then, the mode switching unit 301 changes each unit to the normal control mode. Then, the operator inputs the light quantity command value from another computer or input device to the light quantity command value receiving unit 302 together with the LED identifier.

  Next, the light amount command value conversion unit 303 is calculated based on the correspondence data stored in the correspondence storage unit 304 under the condition that the LED identifiers match, and is stored in the conversion coefficient storage unit. Get the conversion factor that is being used. And using this conversion coefficient and Formula 1, the electric current value which is a drive parameter corresponding to the input light quantity command value is calculated for every LED identifier. Thereafter, a current value corresponding to the light intensity command value is input to each LED 4 as a command to the power supply unit 307, and the power supply unit 307 performs constant current control with the current value received for each LED.

  As described above, in the light irradiation device 1 of the present embodiment, first, in the initial setting, an applied current value for realizing the actual light amount is searched for while measuring the actual light amount for each LED, and the detected applied current value is further detected. Corresponds to the light quantity command value. Further, an applied current value corresponding to a light amount command value other than the actually measured value can be calculated using the corresponding applied current value and light amount command value. Therefore, even if there is an error for each LED, if the same light amount command value is input, a current is applied to each LED 4 with a different current value. As a result, the actual light amount irradiated from each LED 4 becomes the same light amount. , Can solve the problem of variation. Further, for example, when a predetermined irradiation area AR is imaged with a camera, the end portion tends to be captured darkly, but the end portion is irradiated in advance, and an image with uniform brightness can be obtained without any image processing. It will be possible to get as calculated.

  <3> Range change

  Next, the case where the range to be used is changed among the actual light amounts that can be emitted from each LED 4 will be described.

  Basically, the operation is almost the same as <1> initial setting, but the value of the drive parameter associated with the light amount command value is made different. More specifically, when it is desired to narrow the use range of the actual light amount irradiated from the LED 4 as shown in FIG. 9 from the use range of the actual light amount in the initial state shown in FIG. 8, the maximum light amount Lmax is higher than the initial state. When the small desired maximum light amount is reached, the MAX button P4 is pressed, and when the minimum light amount Lmin becomes a desired minimum light amount larger than the initial state, the MIN button P5 is pressed to determine the light amount command value and the drive parameter. Perform the association.

  Then, since the light quantity command value represents the number of gradations, the fact that the width between the maximum value and the minimum value is reduced means that the division is performed with the same number of bits as the natural range. In other words, the actual light quantity that associates the maximum light quantity command value with the minimum light quantity command value can be freely changed by the timing signal generator, so the light quantity command always has the same number of divisions according to the range of use. A drive parameter corresponding to the value can be set. That is, it is possible to always change the light amount with the same resolution as is apparent from FIGS. 8 and 9 assuming that the use range of the actual light amount is changed. This is possible because the light quantity command value is treated as a value such as lux indicating specific brightness, and the actual light quantity corresponding to the specific value is not associated, but the light quantity command value is This is because it is handled as simply indicating magnitude, and is configured so that an arbitrary actual light quantity can correspond to the light quantity command value.

  In addition, since it does not require any particularly complicated control or equipment, it can be realized with a simple configuration.

  Furthermore, for example, the LED 4 whose light amount has dropped due to deterioration or the like cannot output a predetermined maximum light amount, so that the LED 4 can be found at the time of calibration, and maintenance and management are facilitated.

  The present invention is not limited to the above embodiment.

  For example, the drive parameter is preferably a current when a high speed is required, such as for line scanning, but may indicate an ON / OFF ratio when pulse driving is performed by voltage, PWM, or the like depending on the application. In addition, a mechanical light shielding unit (for example, liquid crystal) is disposed in front of the LED or LED group, a driving parameter indicating the light shielding amount is received, and the light shielding unit drives the light shielding unit with a light shielding amount determined by the driving parameter. You may make it provide a drive part. If it is such, since the emitted light amount of LED itself does not change individually and heat amount becomes constant, the dispersion | variation in the lifetime of each LED decreases, and it becomes advantageous for a maintenance.

  Moreover, you may enable it to set the correspondence data of LED4 automatically. Specifically, a plurality of points at which a predetermined actual light amount from the imaging device CMR is obtained can be automatically acquired, and the drive parameter value at that time is automatically set to correspond to a predetermined light amount command value. The correspondence data may be created with Further, the method for measuring the actual light amount from the LED 4 is such that, in addition to the light amount measured by the imaging device CMR, the gradation value of the imaging data output from the imaging device CMR is input to the correspondence data creating unit. Also good. Further, the actual light quantity may be monitored using data in an image processing apparatus that receives image data output from the image capturing apparatus CMR and performs image processing. More specifically, the tone value of image data created from image data in an image processing apparatus such as a computer may be fed back as the actual light quantity of the LED 4. Note that the gradation values of the imaging data and the image data are values obtained by changing the brightness to digital data.

  Further, in the above-described feedback method of the actual light amount, a desired light amount can be obtained more accurately from each LED 4, and in particular, the output from the imaging device CMR is effective as illumination for inspection such as surface inspection. The captured image data is subjected to image processing and fed back from image data created by an image processing apparatus that creates an image for actual inspection. In such a case, since the correspondence relationship between the light amount command value and the actual light amount can be created based on the final brightness in the use of image data, it is particularly effective.

  In the above-described embodiment, it is configured to be switched to the normal control mode and the setting mode, and the correspondence relationship between the light quantity command value and the drive parameter can be updated only when the mode is switched to the setting mode. However, for example, when the drive parameter is forcibly changed by the drive parameter forcible input unit 305 regardless of the setting mode or the like, the light amount command value received by the current light amount command value receiving unit 302 is newly changed. The drive parameters may be associated with each other.

  In the above embodiment, the light quantity command value is input to the light quantity control device 3 from an external computer or the like, and the actual light quantity irradiated from the LED is always kept at a desired value. May be changed by a volume provided in the light quantity control device 3, and the light quantity command value conversion unit 303 may sequentially calculate the corresponding drive parameter every time the volume is changed.

  Further, the correspondence relationship storage unit 304 stores the actual light amount at the time of setting measured by the light amount measurement unit at the time when the association is performed together with the associated light amount command value and the drive parameter. When the command value conversion unit 303 converts the light amount command value received by the light amount command value reception unit 302, a deviation between the actual light amount at normal control measured by the light amount measurement unit and the actual light amount at set time If there is, the drive parameter converted from the light amount command value may be corrected based on the deviation. In this case, since it is necessary to constantly monitor the actual light quantity and provide feedback, for example, always monitor the irradiation light from the LED 4 with a photodiode or the like, and perform feedback at each sampling period, for example, every sampling period. It doesn't matter.

  Further, in addition to determining the actual light amount and measuring the drive parameter at that time to obtain correspondence data, the drive parameter may be determined in advance and the actual light amount at that time may be measured to obtain the correspondence data. It is possible to set not only two measurement points, but also one point or three or more points, and it is possible to arbitrarily set the points.

  That is, the correspondence relationship storage unit 304 stores the first correspondence relationship data, the second correspondence relationship data, and the third correspondence relationship data, and the light quantity command value of each correspondence data is the first light quantity command value, The light quantity command value conversion unit 303 has a first light quantity based on the first correspondence data and the second correspondence data. A first linear function indicating a correspondence relationship between the gradation value of the light amount command value between the command value and the second light amount command value and the drive parameter is calculated, and the first correspondence function data is calculated based on the second correspondence relationship data and the third correspondence relationship data. A second linear function indicating a correspondence relationship between the gradation value of the light amount command value between the two light amount command value and the third light amount command value and the drive parameter is calculated and received by the light amount command value receiving unit 302. The light intensity command value is If the light quantity command value is between the light quantity command value and the second light quantity command value, the drive parameter is calculated based on the first linear function, and the light quantity command value received by the light quantity command value receiving unit 302 is the second light quantity command value. When it is between the third light quantity command values, the drive parameter may be calculated based on the second linear function.

  More specifically, as shown in FIG. 10, the first light quantity command value is the minimum light quantity command value (0), the second light quantity command value is the intermediate light quantity command value (191), and the third light quantity command value is the maximum light quantity command value. The case of (255) will be described as an example. The intermediate light quantity command value is a concept including not only the median value but also any value between the maximum and minimum. Further, the light amounts emitted from the LEDs and desired to be emitted as the actual light amounts when the previous light amount command values are input are set as the minimum actual light amount Lmin, the intermediate actual light amount Lmid, and the maximum actual light amount Lmax. Further, current values to be applied to the respective LEDs in order to obtain respective desired actual light amounts are defined as Imin, Imid, and Imax. Each character is given a subscript number according to the LED identifier.

  As shown in FIG. 10A, the first actual light amount usage range that is the range from the minimum actual light amount Lmin to the intermediate actual light amount Lmid, and the second actual light amount use in the range from the intermediate actual light amount Lmid to the maximum actual light amount Lmax. It is assumed that there are cases where two use ranges are defined as in the range and the control resolution is different in each use range.

  As apparent from FIG. 10A, the first actual light amount use range is narrower than the second actual light amount use range. However, in this embodiment, in the first actual light amount use range, the light can be adjusted more finely than usual, and in the second actual light amount use range, even if the change amount of the light amount command value is not large, the actual light amount changes greatly. I am doing so.

  More specifically, for the light amount command values αmin and αmid associated with the current values Imin and Imid necessary to realize the minimum actual light amount Lmin and the intermediate actual light amount Lmid, the minimum value (0) for the minimum light amount command value αmin. On the other hand, for the intermediate light quantity command value αmid, the ratio of the gradation value of the intermediate light quantity command value to the total number of gradations is larger than the ratio of the first actual light quantity use range in the entire actual light quantity use range. In addition, the intermediate light quantity command value αmin is selected. On the other hand, in the second actual light quantity usage range, the above-described relationship is set to be reversed.

  Thus, the correspondence relationship data in which the light quantity command value and the current value as the drive parameter are paired is stored in the correspondence relationship storage unit 304. Further, the conversion coefficient calculation unit calculates the conversion coefficient by fitting a different linear function for each use range using the following formula.

  More specifically, Equation 2 is used in the first actual light amount usage range, and Equation 3 is used in the second actual light amount usage range.

  Formula 2 I (α) = ((Imid−Imin) / (αmid−αmin)) α + (Imid · αmin−Imin · αmid) / (αmid−αmin)

  Formula 3 I (α) = ((Imax−Imid) / (αmax−αmid)) α + (Imax · αmid−Imid · αmax) / (αmax−αmid)

  Thus, by appropriately selecting the intermediate light quantity command value, the control resolution can be varied for each section.

  In such a case, when the drive parameter is configured to be associated with the maximum value, intermediate value, and minimum value of the light amount command value, the use range of the actual light amount is set small between the maximum value and the intermediate value. The range of use of the actual light amount can be set large between the intermediate value and the minimum value. In other words, for a certain range of the light quantity command value, a narrow range of the actual light quantity is finely divided so that it can be controlled with high accuracy, and the gradation can be changed only roughly for another range of the light quantity command value. You can also. It is possible to freely set the use range of the actual light quantity and its resolution.

  Further, the correspondence relationship between the light quantity command value and the drive parameter may be set by only acquiring one set of correspondence relationship data for each LED. For example, as shown in FIG. 11, when the light quantity command value is zero, the conversion coefficient calculation unit calculates the conversion coefficient by fixing one point such that the applied current value is zero. It doesn't matter. More specifically, the conversion coefficient calculation unit calculates the conversion coefficient by performing fitting within the use range using the following Equation 4.

  Formula 4 I (α) = (Imax / αmax) α

  If this is the case, the relationship between the light amount command value, the drive parameter, and the actual light amount is set for only one point for each LED. More specifically, only the maximum value of the actual light amount to be used is set. Thus, even if the use range changes, the number of gradations of the light quantity command value and the actual light quantity associated with the light quantity command value can be changed appropriately while maintaining the control resolution. Therefore, the light quantity control of each LED can be accurately performed with fewer procedures.

  In terms of mechanism, for example, it may be configured to be detachable so that the drive board 32 can be increased or decreased according to the number of LEDs 4, or the casing 33 that can accommodate the drive board 32 with respect to the casing 33 having the main board 31. May be connected by a cable so as to be increased or decreased. Of course, the light quantity control device 3 may integrate the main board 31 and the drive board 32, or may have another hardware configuration.

  In addition, this light irradiation apparatus 1 is not limited to line illumination, and can be applied as long as it uses one or a plurality of LEDs. In particular, in the case of using one LED, the effect becomes remarkable when the LED is replaced. Moreover, you may make it control the LED group which collected multiple LED as 1 unit. That is, the present invention can provide an effective effect in general illumination using LEDs.

  Also, considering user convenience, a warning signal output unit that outputs a warning signal indicating that the LED is defective when the predetermined actual light amount cannot be obtained even if the adjustment volume is changed within the variable range. It is desirable to further include The warning signal output unit may determine whether or not the LED is defective from the content of the measurement data, and may output a warning signal when determining that the LED is defective.

  Further, either the MAX button P4 or the MIN button P5 may be omitted, and the values of Imax and αmax may be fixed constantly, or the values of Imin and αmin may be fixed constantly.

  In addition, various modifications can be made without departing from the spirit of the present invention.

  As described in detail above, according to the present invention, in the light irradiation device 1 using a plurality of LEDs, as long as the target light amount to be irradiated by each LED is given, the difference in their characteristics is absorbed and given. It is possible to emit light with a target light amount with a simple configuration.

  In addition, various modifications and combinations of embodiments may be performed without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Light irradiation apparatus 2 ... Light emission mechanism 3 ... Light quantity control apparatus 4 ... LED or LED group AR ... Predetermined area | region 307 ... Power supply part 302 ... Light quantity command value reception Unit 303 ... Light quantity command value conversion unit 304 ... Correspondence relationship storage unit 305 ... Drive parameter forced input unit 306 ... Correspondence relationship data creation unit P4, P5 ... Timing signal generation unit

Claims (9)

A light amount control device that controls the amount of light emitted from a light emission mechanism including an LED or LED group toward a predetermined irradiation region,
A power supply unit that accepts a drive parameter such as a supply current value, a supply voltage value, and an ON / OFF ratio in pulse drive as an input, and outputs power determined by the drive parameter to the LED or the LED group;
A light amount command value receiving unit that has a predetermined number of gradations and receives a relative light amount command value indicating a magnitude of the target light amount;
A plurality of correspondence data in which a drive parameter input to the power supply unit and a light amount command value are paired in a state where it is measured that a desired actual light amount is irradiated from the LED or LED group A correspondence storage unit for storing
Based on the light amount command value received by the light amount command value receiving unit and a plurality of correspondence data, the power is converted into a drive parameter corresponding to the light amount command value received by the light amount command value receiving unit. A light intensity command value conversion unit that inputs to the supply unit, and a light irradiation device comprising:
A drive parameter forced input unit for forcibly inputting a desired drive parameter to the power supply unit;
When a drive parameter is forcibly input from the drive parameter forcible input unit, the light amount command value received by the light amount command value receiving unit and the drive parameter forcible input unit are input to the power supply unit. A light quantity control device further comprising: a correspondence data creating unit that creates correspondence data paired with drive parameters and stores the correspondence data in the correspondence storage unit as new correspondence data.   The correspondence data generation unit changes the drive parameter input to the power supply unit by the drive parameter forcible input unit, and the power supply is performed when a desired actual light amount is irradiated from the LED or the LED group. The light quantity control device according to claim 1, wherein the drive parameter input to the unit can be associated with a light quantity command value having an arbitrary gradation value. A timing signal generator for generating a timing signal when a desired actual light amount is emitted from the LED or LED group;
The light quantity control device according to claim 1, wherein the correspondence relationship data creation unit is configured to store new correspondence relationship data in the correspondence relationship storage unit when the timing signal is detected.   The light quantity command value conversion unit includes a first correspondence relationship data in which a first light quantity command value having a first gradation and a first drive parameter corresponding to the first light quantity command value are paired; The gradation value of the light quantity command value based on the second correspondence data in which the second light quantity command value having two gradations and the second drive parameter corresponding to the second light quantity command value are paired And a linear function indicating a correspondence relationship with the drive parameter, and based on the linear function, a drive parameter corresponding to the light amount command value received by the light amount command value receiving unit is calculated, and the power supply unit 4. The light quantity control device according to claim 1, wherein the light quantity control device is configured to input.   The light quantity control device according to claim 4, wherein the first light quantity command value has a minimum gradation value, and the second light quantity command value has a maximum gradation value. The correspondence storage unit stores the first correspondence data, the second correspondence data, and the third correspondence data, and the light quantity command value of each correspondence data is the first light quantity command value and the second light quantity. It has a relationship that increases in the order of the command value and the third light quantity command value,
The light quantity command value conversion unit, based on the first correspondence data and the second correspondence data, the correspondence between the gradation value of the light quantity command value between the first light quantity command value and the second light quantity command value and the drive parameter. A first linear function indicating
Based on the second correspondence data and the third correspondence data, a second linear function indicating the correspondence between the gradation value of the light quantity command value between the second light quantity command value and the third light quantity command value and the drive parameter is calculated. Is what
When the light quantity command value received by the light quantity command value receiving unit is between the first light quantity command value and the second light quantity command value, the drive parameter is calculated based on the first linear function,
When the light quantity command value received by the light quantity command value receiving unit is between the second light quantity command value and the third light quantity command value, the drive parameter is calculated based on the second linear function. Item 6. The light quantity control device according to Item 1, 2, 3, 4 or 5. A light amount measuring unit for measuring the actual light amount in the predetermined irradiation region;
The correspondence relationship storage unit stores the actual light amount at the time of setting measured by the light amount measurement unit at the time when the association is performed together with the associated light amount command value and the drive parameter,
Deviation between the actual light amount at normal control measured by the light amount measurement unit and the actual light amount at set time when the light amount command value conversion unit converts the light amount command value received by the light amount command value reception unit 7. The light quantity control device according to claim 1, wherein the drive parameter converted from the light quantity command value is corrected based on the deviation.   The light quantity control device according to claim 7, wherein the light quantity measurement unit is configured to measure an actual light quantity based on brightness of an image captured in the predetermined irradiation region. A light amount control device according to any one of claims 1 to 8,
A light emitting device including an LED or an LED group.