JP2012064179A - Led illumination device for optical information reading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance flexibility of illumination.SOLUTION: In a ring type external illumination unit 4, an LED substrate 77 and a circuit board 78 are housed inside an outer case composed of a ring-shaped cylindrical front case 75 and a rear case 76 in a state of being laminated while sandwiching a first spacer. A plurality of LEDs 80 for illumination are mounted on the LED substrate 77 having a substantially same size as a ring-shaped cross section of the front case 75. On the circuit board 78, an LED driving circuit, a CPU that controls lighting of the plurality of LEDs 80 mounted on the external illumination unit 4 and controls communication with a bar code reader 2, and a memory M are mounted.

Description

  The present invention relates to an illuminating device used in an optical information reader for reading optical information such as a barcode and a QR code.

  Now that traceability has become widespread, optical information readers are installed in factories, logistics bases, etc., and optical information such as barcodes attached to products and products or optical codes are decoded. This type of optical information reader is called a “bar code reader” or “code reader”.

  The bar code reader irradiates optical information with laser light, visible light, and infrared light, and captures the reflected light with an optical reading element (imaging element). Then, the information recorded in the optical information is analyzed from this captured image.

  As can be seen in Patent Document 1, the bar code reader includes an illumination LED, and optical information is captured while illuminating the visual field range with the illumination LED. Further, external illumination separate from the barcode reader is used as required (Patent Document 2).

JP 2008-33465 A JP 11-338966 A

  Depending on the surface properties of the workpiece and the work environment, it becomes difficult to read optical information even with the same illumination, so illumination in the field of view is important for improving the reading accuracy of the barcode reader. In particular, when a bar code reader is intended to be miniaturized as disclosed in Patent Document 1, illumination in the visual field range becomes more difficult.

The objective of this invention is providing the LED illuminating device for optical information readers which can improve the freedom of illumination.
It is a further object of the present invention to provide an LED illumination device for an optical information reading device that can increase the flexibility of illumination without causing an increase in the size of the LED illumination device.

According to the present invention, the above technical problem is
An LED illumination device that is used in an optical information reader that reads optical information from a work with optical information, and in which illumination LEDs are arranged in a ring shape around the optical axis of the optical information reader,
A plurality of lighting LEDs in a first row arranged on a first circumference;
A plurality of illumination LEDs in a second row arranged on a second circumference having a diameter different from the first circumference;
A plurality of illumination LEDs belonging to each block are connected in series for each block obtained by dividing the first row and the second row in the circumferential direction, and a plurality of blocks belonging to the block are turned ON / OFF. A block circuit for generating a state in which a voltage can be applied to the illumination LED
A constant current circuit connected to each block circuit;
A plurality of lighting LEDs connected in series to each block circuit is divided into the first and second columns, and a column switch connected in parallel with the lighting LEDs in each column,
LED lighting for an optical information reading device, wherein partial illumination can be performed with a lighting pattern set by a user for each preset area by controlling ON / OFF of the block switch and the column switch This is accomplished by providing a device.

  That is, according to the present invention, in an LED lighting device that is a ring-shaped surface light source, a lighting pattern can be arbitrarily set so that illumination is performed in some areas and other areas are not lit by a combination of block switches and column switches. Can be set to Since this setting is left to the user, the user can increase the reading accuracy of the optical information by setting the most suitable lighting pattern by the lighting pattern suitable for the work environment and the surface texture of the workpiece.

  In a preferred embodiment of the present invention, the LED illumination device according to the present invention is an external illumination unit that can be connected to a barcode reader as necessary. The external illumination unit includes an LED substrate on which the plurality of LEDs are mounted, A circuit board provided with a drive circuit for driving the plurality of LEDs, and the LED board and the circuit board are stacked one above the other through spacers. As a result, even if the mounting density of the LEDs for illumination is increased with respect to the LED substrate, a circuit board on which the LED driving circuit is mounted is prepared separately from the LED board on which the lighting LED is mounted. The density of the LED for illumination can be increased without being restricted. And since an LED board and a circuit board are laminated | stacked up and down via the spacer, the enlargement of an external illumination unit is not caused. Other objects and advantages of the present invention will become apparent from the detailed description of the following examples.

1 is an overall configuration diagram of a barcode reader system. It is a perspective view of the barcode reader which is an optical information reader. It is the figure which looked at the arrangement | positioning of the various board | substrates arrange | positioned inside a barcode reader from diagonally forward. FIG. 4 is a diagram related to FIG. 3, and is a diagram of an arrangement of various substrates arranged inside the barcode reader as viewed obliquely from the rear. It is a figure for demonstrating the connection relation of the various board | substrates incorporated in a barcode reader. It is a figure for demonstrating arrangement | positioning of the chassis incorporated in a barcode reader, the main board | substrate assembled | attached to this chassis, a power supply board, and a sub board | substrate. It is a figure for demonstrating the various elements assembled | attached to a chassis. It is the figure which looked at the camera module from diagonally backward. It is the figure which looked at the camera module from diagonally forward. It is a conceptual diagram for demonstrating the internal structure of a camera module. It is a figure which shows the relationship between a camera module and various board | substrates, and is accommodated in the main case of a barcode reader in this state. It is a figure which shows the relationship between a camera module and various board | substrates similarly to FIG. 11, It is a figure which shows the example which mounted the heat conductive rubber which is a heat radiating member on a power supply board and a main board | substrate as a preferable example. FIG. 13 is a diagram for explaining a state in which the heat conductive rubber is in contact with the power supply substrate, the main substrate, and the main case in relation to FIG. 12. It is a figure for demonstrating attaching an LED board (internal illumination board) to the front end surface of a pair of rod-shaped extension part extended ahead from a main case, and fixing the front end of a power supply board and a main board to an extension part. is there. It is a figure for demonstrating that the main case and its open | released rear end of a barcode reader are closed by a rear case, and is an exploded perspective view which shows the state which fixed the connector board | substrate to this rear case. It is a front view of the main case which accommodated the built-in thing shown in FIG. FIG. 17 is a front view of the main case with the camera module removed from FIG. 16. It is a figure for demonstrating one means to adjust the focal distance of the camera module fixed to a main case. It is a figure for demonstrating one means to adjust the shift | offset | difference of the optical axis of the camera module fixed to a main case. It is a figure which shows the state which attached the external illumination unit to the barcode reader. It is a disassembled perspective view of an external illumination unit. It is a perspective view of the LED board carrying LED built in an external illumination unit. It is a figure for demonstrating the attachment relationship of the two board | substrates integrated in an external illumination unit. It is a figure which shows an example of the seal structure of the front case and rear case which comprise the outer case of an external illumination unit. It is a figure which shows the other example of the seal structure of the front case and rear case which comprise the outer case of an external illumination unit. It is the fragmentary perspective view which extracted the upper end part of the plate member which is a tool for attaching an external illumination unit to a barcode reader. It is the fragmentary perspective view which extracted a part of plate member in order to demonstrate the fastening structure of a plate member and a barcode reader. It is a figure which shows the modification of the attachment metal fitting provided in the plate member. It is sectional drawing of the attachment metal fitting shown in FIG. It is sectional drawing of the state which attached the small diameter exclusive external illumination unit to the barcode reader. It is sectional drawing of the state which attached the large diameter exclusive external illumination unit to the barcode reader. It is a figure for demonstrating that LED contained in the internal illumination unit which is a surface light source incorporated in the barcode reader is divided into a plurality of areas, and lighting control is performed for each area. FIG. It is a front view of a large-diameter dedicated external lighting unit, and is a diagram for explaining that LEDs included in the external lighting unit are divided into a plurality of areas and lighting control is performed for each area. It is a front view of a small-diameter dedicated external lighting unit, and is a diagram for explaining that the LEDs included in the external lighting unit are divided into a plurality of areas and lighting control is performed for each area. It is a figure which shows an example of the LED drive circuit integrated in the internal illumination unit and the external illumination unit. It is a systematic diagram for controlling the partial illumination of an internal illumination unit and an external illumination unit. It is a figure which shows the specific example of a block switch and a column switch mechanism. It is a figure for demonstrating the concept of "block" "column" regarding LED drive of internal illumination and external illumination. It is a whole system diagram relevant to the lighting control of the setting area regarding the partial illumination of an internal lighting unit and an external lighting unit. It is a block diagram of the barcode reader system related to FIG.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

Bar code reader system (Figure 1) :
FIG. 1 is a diagram for explaining an outline of a bar code reader system. Referring to FIG. 1, a bar code reader system 1 includes a bar code reader 2 which is a two-dimensional information reading device, and a personal computer 3 connected to the bar code reader 2 as necessary. Various settings are performed using the personal computer 3 while confirming an image captured by the reader 2 with the personal computer 3. In the barcode reader system 1, a ring-type external illumination unit 4 is further connected to the barcode reader 2 as necessary, and together with the internal illumination unit 5 of the barcode reader 2 or the internal illumination unit 5. The operation is stopped and the work is illuminated only by the external illumination unit 4.

  The ring-type external lighting unit 4 is a dedicated product for the bar code reader system 1, and it is preferable to prepare a plurality of different types of external lighting units 4. Of course, it is also possible to incorporate a lighting unit other than a dedicated product as the external lighting unit 4.

  The bar code reader system 1 is installed in an article conveyance path in a factory that manufactures goods or articles printed or engraved with optical information or optical codes such as bar codes and QR codes. The information recorded in the optical information printed on is read and transferred to the personal computer 3 for information analysis. The “optical information reader” is generally called “bar code reader” or “code reader”, and the industry term “bar code reader” is used here.

  Further, in the illustrated example, as disclosed in FIG. 1, various settings of the barcode reader system 1 are performed using the personal computer 3 by installing a setting program in the personal computer 3. Of course, the bar code reader 2 is provided with, for example, a display means with a touch panel, and the bar code reader 2, the internal illumination unit 5 (FIG. 3) and / or the external illumination 4 (FIGS. 20 and 21) are set using this display means. You may be able to work.

Bar code reader 2 (FIGS. 2 to 19) :
FIG. 2 is a perspective view showing the appearance of the barcode reader 2. The bar code reader 2 has a main case 6 having a polygonal cross section and a cylindrical front case 7 fixed to the front end of the main case 6, and the internal lighting unit described above is provided in the cylindrical front case 7. 5 is built-in. As can be seen from FIG. 2 and the like, the main case 6 preferably has a substantially square cross-sectional shape.

The barcode reader 2 includes a plurality of substrates that are independent of each other. With reference to FIGS. 3 to 5, the plurality of substrates included in the barcode reader 2 are as follows.
(1) Main board 10:
The main substrate 10 is equipped with a CPU and a memory M, and an image is transferred to the memory M and processed by a DSP (digital signal processor). The CPU of the main board 10 controls the barcode reader 2 including the internal lighting unit 5 and performs communication with the external lighting unit 4.
(2) Power supply board 11:
A power source for the barcode reader 2 is generated. An isolated input / output circuit is implemented.

(3) Sub-board 12:
A large-capacity memory is mounted, and acquired images and various settings are stored in the large-capacity memory. In the main board 10 having a limited size and shape, elements that could not be mounted on the main board 10 are mounted.
(4) CMOS substrate 13 (light receiving substrate):
A CMOS image sensor (optical reading element) is mounted, and an image is acquired and transferred to the main board 10. A pointer LED 40 (FIG. 10) is mounted.

(5) LED substrate 14:
It is a disk-shaped board | substrate provided with the circular opening 14a which comprises the internal illumination unit 5, The some LED80 for illumination is mounted in this LED board 14 (FIG. 32 mentioned later), and lighting of this some LED80 for illumination Execute control. The plurality of illumination LEDs 80 are arranged on a plurality of concentric circles having different diameters around the optical axis of the lens assembly 36 of the barcode reader 2 described later. The plurality of illumination LEDs 80 mounted on the internal illumination unit 5 (LED substrate 14) are controlled to be lit in divided areas as will be described later. The LED board 14 is provided with a constant current circuit for supplying a constant current to a plurality of illumination LEDs belonging to each area.
(6) Connector board 15:
This is a board constituting an input / output interface with an external power supply, IO, RS232C, Ethernet (registered trademark), and external illumination unit 4. The external lighting unit 4 is supplied with power from the power supply board 11.

  Referring to FIGS. 3 and 4, main board 10 and power supply board 11 are arranged to face each other, and these main boards 10 are located in regions sandwiched between the side edges of main board 10 and power supply board 11. The sub-board 12 is disposed so as to be orthogonal to the power supply board 11. The arrangement positions of the sub board 12 and the main board 10 may be replaced with each other. The main board 10, the power supply board 11, and the sub board 12 are arranged along the three side surfaces of the bar code reader 2 adjacent to three side surfaces of the four side surfaces of the main case 6 having a rectangular cross section. . A CMOS substrate 13 is located in a space surrounded by the main substrate 10, the power supply substrate 11, and the sub substrate 12, and the CMOS substrate 13 is disposed on one vertical plane orthogonal to the substrates 10 to 12. Further, the LED substrate 14 and the connector substrate 15 are positioned parallel to the CMOS substrate 13 and facing each other with the CMOS substrate 13 interposed therebetween.

  FIG. 5 is a diagram for explaining the connection relationship between the substrates 10 to 15 described above. The main board 10 is connected to the power supply board 11 by a first FFC 20 (Flexible Flat Cable), connected by a sub board 12 and a second FFC 21, and connected to the CMOS board 13 by an FPC (Flexible Printed Circuit) 22, The lighting unit 4 is connected to the LED board 14 by the third FFC 23, and is connected to the connector board 15 by the first harness 24. The power supply board 11 is also connected to the LED board 14 of the internal lighting unit 5 by the second harness 25, and a power source for causing the illumination LED mounted on the LED board 14 to emit light is supplied from the power supply board 11 to the LED board 14. Supplied. The power supply board 11 and the connector board 15 are connected by two harnesses 26 and 27 and the FFC 28.

  Referring to FIG. 5 again, it should be noted that the main board 10 and the power supply board 11 have substantially the same size and shape. In other words, the main board 10 is designed to have substantially the same size and shape as the power supply board 11, and electronic components that could not be mounted on the main board 10 due to this restriction are mounted on the sub board 12.

  6 and 7, the main substrate 10, the power supply substrate 11, the sub substrate 12, and the CMOS substrate 13 are assembled to a chassis 30 that is a resin molded product. As best seen in FIG. 7, the chassis 30 has a box shape having a substantially square cross-sectional shape that is substantially similar to the cross-sectional shape of the main case 6, and closes one side surface 30a of this box shape. The five surfaces are open. The main substrate 10, the power supply substrate 11, and the sub substrate 12 are disposed on the three open side surfaces 10b to 10d, respectively. The resin molded chassis 30 is open front and rear, and a camera module 32 is inserted through one end opening 30f (FIG. 7). The camera module 32 inserted into the chassis 30 is surrounded by the main substrate 10, The power supply board 11 and the sub board 12 are located, and the camera module 32 is surrounded by the main board 10, the power supply board 11 and the sub board 12.

  Referring to FIGS. 8 and 9, the camera module 32 has a camera holder 35 made of a die-cast product such as aluminum. The camera holder 35 is opposed to a holder main body 35a having a rectangular cross section and a holder main body 35a. A pair of arms 35b extending forward and parallel to each other from the side surfaces, and a pair of attachment portions 35c extending in the direction away from the front ends of the pair of arms 35b. The CMOS substrate 13 is fixed to the holder main body 35a by a plurality of screws 37 on the rear end surface opened rearward (FIG. 8).

  For positioning the main board 10 and the power supply board 11, six claws 38 are integrally formed on the chassis 30 (FIG. 7), and the main board 10 and the power supply opposite to the main board 10 are formed using the six claws 38. The substrate 11 is positioned on each of the two opposite side surfaces 30b and 30d that the chassis 30 is open. The main substrate 10 is formed with a notch 10a for receiving the claw 38 (FIG. 7). Similarly, a notch 11a is formed in the power supply substrate 11 (FIG. 3). Referring to FIG. 7, rectangular sub-board 12 has a pair of through holes 12a and 12b at diagonal corners, and a pair of chassis 30 corresponding to the pair of through holes 12a and 12b. A through hole 30g (one through hole is not shown in the drawing for drawing reasons) is formed, and the sub-board 12 is screwed to the chassis 30 by aligning these through holes 12a, 12b, 30g.

Arrangement of pointer LEDs (FIG. 10) :
The camera module 32 includes a cylindrical lens assembly 36, and the lens assembly 36 is disposed between a pair of arms 35 b and 35 b of the camera holder 35. Referring to FIG. 10, the CMOS substrate 13 is fixed to the rear end opening of the holder main body 35a using screws 37 (FIG. 8). A pair of pointer LEDs 40 and 40 are mounted on the CMOS substrate 13. In relation to the pointer LED 40, a diffusion sheet 41 is disposed in the holder body 35a immediately in front of each pointer LED 40. The lights of the two pointer LEDs 40 are irradiated forward through the diffusion sheet 41 and the lens assembly 36, respectively, and indicate two points separated from each other in the field of view of the barcode reader 2. Reference numeral 43 in FIG. 10 indicates a CMOS image sensor which is an optical reading element, and the optical reading element 43 is mounted on the CMOS substrate 13.

  By incorporating the pointer LED 40 in the camera module 32, the relative position between the optical reading element 43 and the pointer LED 40 can be easily maintained, and the bar code reader 2 can be easily downsized. In particular, since the pointer LED 40 shares the lens assembly 36 of the barcode reader 2 with the optical reading element 43, a dedicated lens for the pointer LED 40 is not required, and the barcode reader 2 can be easily downsized. is there.

  In the camera module 32, the distance between the optical reading element (imaging element) 43 and the lens assembly 36 is very large as compared with the conventional one, and optical information such as a bar code and a QR code is very minute with high resolution. It has the feature that it can be read to the area. Thus, when the camera module 32 having a large length in comparison with the conventional case is accommodated in the barcode reader 2, attention should be paid to the above-described substrate arrangement. That is, by introducing the technical idea that the camera module 32 is surrounded by the main board 10, the power supply board 11, and the sub board 12, the long camera module 32 is accommodated in the outer case while downsizing the barcode reader 2. can do.

Incidentally, the specifications of the camera module 32 are as follows.
(1) Optical magnification: 0.6 to 1.0 times (in the examples, 0.823 times);
(2) Field of view range: 7.5 mm x 4.8 mm to 4.5 mm x 2.9 mm (5.5 mm x 3.5 mm in the example);
(3) Distance from the optical reading element to the front lens: 35 mm or more (40 mm in the embodiment).

  FIG. 11 is a perspective view of an assembly in which the substrates 10, 11, 12 and the camera module 32 are assembled to the chassis 30. FIG. 12 shows a state in which a heat conductive rubber 45 is installed on the main board 10 and the power supply board 11 as a heat radiating member having cushioning properties and excellent heat conductivity. If there is a need for heat dissipation of the barcode reader 2, it is accommodated in the main case 6 (FIG. 2) having a rectangular cross section with the heat conducting rubber 45 attached in the manner illustrated in FIG. 12 (FIG. 13).

  Since the main board 10 and the power supply board 11 are disposed adjacent to and along different side surfaces of the main case 6 having a polygonal cross section made of a metal material having excellent heat conductivity, the heat of the main board 10 and the power supply board 11 can be obtained. Since the camera module 32 can be accommodated in a space surrounded by the main board 10 and the power supply board 11, the barcode reader 2 can be further reduced in size. In particular, heat dissipation efficiency can be increased by interposing a heat dissipation member such as the heat conductive rubber 45 between the main board 10, the power supply board 11 and the main case 6. Miniaturization is possible.

  Reference numeral 46 in FIGS. 13 and 15 denotes a rear case, which is detachably attached to the rear end opening of the main case 6 and closes the main case 6. A connector board 15 is attached to the rear case 46, and the connector board 15 is fixed to the rear case 46 with screws 47 (FIG. 15). The main case 6, the front case 7, and the rear case 46 constituting the outer case of the barcode reader 2 are preferably made of, for example, a metal material excellent in heat conduction, for example, a heat transfer material such as aluminum.

  Referring to FIG. 6, the main board 10 and the power supply board 11 have through holes 50 and 51 in the narrow part of the front end, respectively. The main case 6 of the barcode reader 2 has a pair of rod-like extension portions 6a extending forward and parallel to the inside of the cylindrical front case 7 (FIG. 15).

  Referring to FIG. 14 in which the front end portion of the main case 6 is extracted, the pair of extension portions 6 a of the main case 6 are formed in the through holes 50 and 51 associated with the narrow front end width portions of the main board 10 and the power supply board 11. Holes 52 and 53 are formed, and the main board 10 and the power supply board 11 are fixed to the main case 6 (extension portion 6a) using screws 54 inserted into the through holes 52 and 53. As a result, the main board 10 and the power board 11 positioned by the three claws 38 of the chassis 30 are each fixed to the extended portion 6 a extending forward of the main case 6 by one screw 54. In other words, the chassis 30 is fixed to the main case 6 by the two screws 54 in total. In order to facilitate the work of fastening the screw 54 and the work of removing the screw 54, it is preferable to mount a nut 55 to which the screw 54 is screwed into the through hole 50 of the main board 10 and the through hole 51 of the power supply board 11. . A ring-shaped LED board 14 is fixed to the front end face of the pair of rod-like extension portions 6 a of the main case 6 using screws 60. The ring-shaped LED substrate 14 is arranged around the lens assembly 36, and a plurality of illumination LEDs 80 mounted on the LED substrate 14 form a ring-shaped surface light source positioned on the outer peripheral side of the lens assembly 36. The

  FIG. 17 is a view of the main case 6 as viewed from the front. The main case 6 has a pair of left and right mounting seats 62 on its front end surface, and the camera module 32 is fixed to the main case 6 using the pair of mounting seats 62. FIG. 16 is a front view of the main case 6 with the camera module 32 incorporated therein. FIG. 17 is a front view of the main case 6 drawn with the camera module 32 removed.

  By fixing the camera module 32 to the main case 6 that is a metal molded product, the positioning accuracy of the camera module 32 can be increased and the positioning accuracy of the visual field range can be increased as compared with the case where the camera module 32 is fixed to the chassis 30. .

  An assembly in which the main board incorporated in the barcode reader 2, that is, the power supply board 10, the main board 12 and the like, and the camera module 32 including the lens assembly 36 are assembled in the chassis is built in the outer case (main case 6). By adopting the configuration, by preparing a plurality of types of camera modules 32, a plurality of types of barcode readers 2 can be provided to the user using the same outer case. Further, it is possible to manufacture the barcode reader 2 using the same power supply board 10 and the main board 12 for the different types of camera modules 32 and using the same outer case.

  The pair of left and right mounting portions 35 c of the camera module 32 described above are seated on the pair of left and right mounting seats 62 of the main case 6, and each mounting portion 35 c is fixed to the corresponding mounting seat 62 using four screws 63. (FIG. 16).

  A spacer 65 is interposed between the mounting seat 62 of the main case 6 and the mounting portion 35c of the camera module 32 (FIG. 18). As the spacer 65, a plurality of types of spacers 65 having different thickness dimensions are prepared in advance, or a single or a plurality of spacers 65 having the same thickness dimension are stacked to adjust the focal length variation of the barcode reader 2. It is good. In addition, by using a plurality of types of spacers 65 having different thickness dimensions to make the focal length of the barcode reader 2 different, the barcode reader 2 having a different focal length can be shared with the user while sharing the same outer case. Can be provided. Also, a plurality of types of spacers 65 having different thickness dimensions are prepared, and the optical axis of the camera module 32 is adjusted using the spacers 65 having different thickness dimensions so that the optical axis of the camera module 32 becomes a regular optical axis. This should be done (FIG. 19).

Dedicated external lighting unit 4 (FIGS. 20 to 31) :
FIG. 20 shows a state in which the dedicated external illumination unit 4 is attached to the barcode reader 2, and reference numeral 70 denotes a cable that connects the barcode reader 2 and the external illumination unit 4. The external illumination unit 4 is supplied with power from the barcode reader 2.

  The external illumination unit 4 having a ring-shaped outer shape has a circular outer contour, and includes a circular opening 4a at the center thereof. The center of the circular opening 4a and the optical axis of the lens assembly 36 of the barcode reader 2 The bar code reader 2 is positioned so as to match. A stand 71 is prepared for positioning the barcode reader 2. As will be described in detail later, the stand 71 has a pair of plate members 72 bolted to the back surface of the external lighting unit 4 and an attachment for placing the barcode reader 2 at an arbitrary height position of the plate members 72. It is comprised with the metal fitting 73.

  First, the structure of the external illumination unit 4 will be described with reference to FIG. FIG. 21 is an exploded perspective view of the external lighting unit 4. In the external lighting unit 4, an LED board 77 and a circuit board 78 are arranged in an outer case including a ring-shaped cylindrical front case 75 and a rear case 76, and a stack connector 79 (FIG. 21) and a first spacer 82. They are accommodated in a stacked state via (FIG. 23).

  A plurality of LEDs for illumination 80 are mounted on a ring-shaped LED substrate 77 having the same size as the ring-shaped cross section of the ring-shaped cylindrical front case 75. The ring-shaped circuit board 78, which is preferably substantially the same size as the ring-shaped LED board 77, controls lighting of a plurality of LEDs 80 mounted on the external illumination unit 4 in addition to the LED drive circuit. A CPU that controls communication with the barcode reader 2 and a memory M (FIG. 1) are mounted. Referring to FIG. 23, the LED board 77 and the circuit board 78 are of course electrically connected, but the LED board 77 and the circuit board 78 are fixed to each other by the first spacer 82 described above. In addition, the LED substrate 77 is fixed to the rear case 76 by the second spacer 81. In other words, the circuit board 78 is fixed to the rear case 76 via the LED board 77.

  In particular, when a Fresnel lens 102 (FIG. 30), which will be described later, is adopted for the front case 75, the relative positioning of the illumination LED 80 of the LED substrate 77 and the front case 75 becomes important. In the example of FIG. 23, the LED board 77 is positioned on the front case 75 via the rear case 76, so that the front case 75 and the LED board 77 are not only relatively positioned, but also the LED board 77. Assembling work of the circuit board 78 is easy.

  As a first modification, regarding the installation structure of the LED board 77 and the circuit board 78, the circuit board 78 may be directly fixed to the rear case 76 via a spacer without the LED board 77 interposed. As a second modification, the circuit board 78 may be fixed to the rear case 76 via a spacer, and the LED board 77 may be fixed to the circuit board 78 via another spacer.

  24 and 25, when the outer case of the external lighting unit 4 is configured in such a manner that the rear case 76 is fitted into the rear end opening of the ring-shaped cylindrical front case 75, as shown in FIG. The adhesive 85 is applied to the peripheral surface of the front case 75 and fitted into the front case 75 or the adhesive 85 is applied to the front case 75 and then the ring-shaped disk-shaped rear case 76 is fitted. The rear case 76 is fitted into the front case 75. After that, the adhesive 85 and the sealing agent are interposed in the gap between the front case 75 and the rear case 76 by filling the gap 85 with the adhesive 85 and the sealing agent. You may make it ensure the sealing performance of a case. In this case, both the screws 75 and 76 may be fixed using screws 86 as necessary.

  Referring to FIG. 25, packing 87 may be interposed between front case 75 and rear case 76, and sealing performance may be secured by this packing 87.

Positioning mechanism of the dedicated external illumination unit 4 (FIGS. 26 to 29) :
26 to 27 are detailed views of the above-described stand 71 (FIG. 20). Referring to FIGS. 20 and 26, the pair of rectangular plate members 72 standing from the back surface of the external lighting unit 4 and adjacent to the central circular opening 4a face each other in the diameter direction of the central circular opening 4a. It extends in parallel.

  The plate member 72 has a guide slit 72a extending in the vertical direction, and has at least one sub slit 72b parallel to the guide slit 72a.

  The mounting bracket 73 has a form including left and right folded portions 73a that cross the plate member 72 and engage with both side edges of the plate member 72, and has a spring property. A screw 74 is preferably attached to the central portion of the mounting bracket 73 so as not to fall off.

  The screw 74 is screwed into a screw hole 89 (FIGS. 15 and 27) of the barcode reader 2 disposed between the pair of plate members 72. The barcode reader 2 includes a protruding pin 90 that is received in the guide slit 72a of the plate member 72 (FIGS. 2 and 15). Two protruding pins 90 are provided on the mutually opposing side surfaces of the main case 6 of the barcode reader 2, and the line connecting the two protruding pins 90 is parallel to the optical axis of the barcode reader 2. . More specifically, two projecting pins 90 are provided on each of the opposing side surfaces of the main case 6 having a rectangular cross section, and the two projecting pins 90 are provided at one end and the other end of the side surface of the main case 6. Has been placed. A screw hole 89 for receiving the screw 74 of the mounting bracket 73 is formed in the front end portion (the end portion on the front case 7 side) of the main case 6.

  When the bar code reader 2 is positioned at a desired height position of the pair of plate members 72 by loosening the screws 74 of the mounting bracket 73 having spring properties, the mounting bracket 73 is brought into close contact with the plate member 72 by screwing in the screws 74. By doing so, the barcode reader 2 is fixed to the plate member 72. In addition to this, a screw hole 92 (FIGS. 2 and 15) is provided in a side surface (for example, the rear case 46) of the barcode reader 2, and the plate member 72 and the bar are fixed using a second screw 93 screwed into the screw hole 92. The code reader 2 may be fastened (FIG. 20). The second screw 93 is disposed in the sub slit 72 b of the plate member 72. Thereby, the mutually opposing side surfaces of the barcode reader 2 are fixed to each plate member 72 by the two screws 74 and 93 that are spaced apart in the vertical direction and the width direction.

  As best understood from FIG. 20, the guide slit 72 a extends straight from one end to the other end in the longitudinal direction of the plate member 72 and parallel to the optical axis of the barcode reader 2. Thereby, the height position of the barcode reader 2 can be adjusted while keeping the optical axis of the barcode reader 2 constant.

  The sub slit 72 b extends in parallel with the guide slit 72 a, but the lower end of the sub slit 72 b ends at the middle portion in the longitudinal direction of the plate member 72. Thus, by terminating the lower end of the sub-slit 72b at the intermediate portion in the height direction of the plate member 72, there is the following advantage. When the first screw 74 of the mounting bracket 73 and the second screw 93 inserted into the sub slit 72b are both loosened in order to adjust the height position of the barcode reader 2, basically, the mounting bracket 73 The bar code reader 2 keeps its position as long as the user does not raise or lower the bar code reader 2 due to the spring property of the bar code. It is possible to prevent the code reader 2 from being damaged. This is because the bar code reader 2 is dropped so that the lower end of the sub-slit 72b ends at a relatively high position, and the second screw 93 screwed to the bar code reader 2 is connected to the sub-slit 72b. The lower end of the sub slit 74b functions as a stopper, so that the barcode reader 2 can be prevented from dropping excessively.

  28 and 29 show a modification of the mounting bracket 100 according to a modification. The mounting bracket 100 has a free end portion 101 that extends upward at the middle portion of the left and right folded portions 73a and then reverses and extends downward. The first screw 74 cannot be removed by the screw holder 74a at the free end portion 101. Is attached. According to the mounting bracket 100 of this modification, even if the first screw 74 is completely detached from the barcode reader 2, it is avoided that the first screw 74 is inadvertently dropped from the mounting bracket 100. be able to.

Type of dedicated external lighting unit 4 (FIGS. 30 and 31) :
30 and 31 show a state in which the external illumination unit 4 is attached to the barcode reader 2. FIG. 30 shows a first type external illumination unit 4A having a small diameter with a relatively small number of LEDs 80. FIG. A large-diameter second type external illumination unit 4B having a relatively large number of LEDs 80 is shown. When the first and second types of external illumination units 4A and 4B are prepared, the user can use the first and second external illuminations 4A and 4B depending on the environment in which the barcode reader system 1 is installed. . This model information is stored in the memory M (FIG. 1) of the external illumination unit 4, and when connected to the barcode reader 2, the barcode reader 2 stores the model information stored in the memory M of the external illumination unit 4. , The external lighting unit 4 is recognized, and thereby connection setting with the external lighting unit 4 is executed.

  The small-diameter external illumination unit 4A having a relatively small number of illumination LEDs 80 has a Fresnel lens 102 in the light-transmitting portion of the front case 75 (FIG. 30). The light of the LED 80 for illumination can be accommodated in the field-of-view range of the barcode reader 2 while arranging the LED 80 for illumination to be directed downward without being inclined. Since the illumination LEDs 80 can be arranged directly below, the mounting density of the illumination LEDs 80 of the small-diameter external illumination unit 4A can be increased. On the other hand, in the large-diameter external illumination unit 4B having a relatively large number of LEDs 80, each illumination LED 80 is mounted on the LED substrate 77 in a state of being inclined toward the field of view of the barcode reader 2.

Partial illumination of the internal lighting unit 5 (FIG. 32) :
FIG. 32 is a plan view of the LED substrate 14 built in the barcode reader 2. On the ring-shaped LED substrate 14, a large number of illumination LEDs 80 are arranged almost uniformly over the entire circumference. The illumination LEDs 80 are arranged at substantially the same intervals on three concentric circles spaced in the radial direction. More specifically, the plurality of illumination LEDs 80 are arranged on a plurality of concentric circles having different diameters around the optical axis of the lens assembly 36 of the barcode reader 2.

  The ring-shaped LED substrate 14 is divided into four blocks at equal intervals in the circumferential direction, and is partially illuminated in units of a total of eight areas formed by dividing each block into two in the radial direction. Specifically, one row on the outermost periphery is divided into four regions at 90 ° intervals. This is illustrated as an outer periphery first area AEout1, an outer periphery second area AEout2, an outer periphery third area AEout3, and an outer periphery fourth area AEout4. The innermost and middle two rows are divided into four regions at 90 ° intervals. This is illustrated as an inner circumference first area AEin1, an inner circumference second area AEin2, an inner circumference third area AEin3, and an inner circumference fourth area AEin4. The LEDs 80 belonging to each of the areas AEout1 to out4 and in1 to in4 are positioned so as to be uniformly distributed in each area.

  Lighting can be controlled in units of the divided areas AEout1 to out4 and AEin1 to in4 of the internal lighting unit 5. The lighting control divided into these areas may include control of the light emission amount of the LED 80.

Partial illumination of the large-diameter external lighting unit 4B (FIG. 33) :
FIG. 33 is a plan view of the LED board 77 of the external illumination unit 4, and more specifically, the LED board 77 of the large-diameter external illumination unit 4B is illustrated. A large number of illumination LEDs 80 are arranged on the ring-shaped LED substrate 77 almost uniformly over the entire circumference. The illumination LEDs 80 are arranged at substantially the same interval on four concentric circles spaced in the radial direction. More specifically, the plurality of illumination LEDs 80 are arranged on four concentric circles having different diameters around the optical axis of the lens assembly 36 of the barcode reader 2.

  The large-diameter external lighting unit 4B is divided into eight blocks at equal intervals in the circumferential direction, and partial illumination is performed in units of a total of 32 areas formed by dividing each block into four in the radial direction. Is set to Specifically, the ring-shaped LED substrate 77 is divided into eight areas at 45 ° intervals in the outermost row. This is illustrated by the outer periphery first area AEout1 to the outer periphery eighth area AEout8. The next row is also divided into 8 areas at 45 ° intervals. This is illustrated by the outer middle first area AEmid1 to the outer middle eighth area AEmid8. The next row is also divided into 8 areas at 45 ° intervals. This is illustrated by the outer middle ninth area AEmid9 to the outer middle sixth area AEmid16. The innermost section is divided into eight areas at 45 ° intervals. This is illustrated by the inner circumference first area AEin1 to the inner circumference eighth area AEin8. Even in the large-diameter external illumination unit 4B, illumination can be controlled in units of a total of 32 areas. Even in the external illumination unit 4B, it is possible to control the light emission amount of the LED 80 for each area.

Partial illumination of the small-diameter external illumination unit 4A (FIG. 34) :
FIG. 34 is a plan view of the LED board 77 of the small-diameter external illumination unit 4A. A large number of illumination LEDs 80 are arranged on the ring-shaped LED substrate 77 almost uniformly over the entire circumference. The illumination LEDs 80 are arranged at substantially the same intervals on three concentric circles spaced in the radial direction. More specifically, the plurality of illumination LEDs 80 are arranged on three concentric circles having different diameters around the optical axis of the lens assembly 36 of the barcode reader 2.

  The ring-shaped LED substrate 77 is divided into 8 regions at 45 ° intervals in the outermost row. This is illustrated by the outer periphery first area AEout1 to the outer periphery eighth area AEout8. The middle row is also divided into eight regions at 45 ° intervals. This is illustrated by the outer middle first area AEmid1 to the outer middle eighth area AEmid8. The inner circumferential row is also divided into eight regions at 45 ° intervals. This is illustrated by the inner circumference first area AEin1 to the inner circumference eighth area AEin8. Even in the small-diameter external illumination unit 4A, partial illumination can be set in a total of 24 areas. The lighting control divided into these areas may include control of the light emission amount of the LED 80. In addition, you may make it vary the color of illumination by LED80 for illumination for the area set as partial illumination.

LED drive circuit of external illumination unit 4 (FIG. 35) :
FIG. 35 shows a part of the LED drive circuit. The LED driving circuit shown in the drawing can turn on the LEDs 80 for each area and supply a constant current to the plurality of illumination LEDs 80 belonging to each area.

  For example, in the case of the small-diameter outer illumination unit 4A shown in FIG. For example, the outer periphery first area AEout1, the intermediate first area AEmid1, and the inner periphery first area AEin1 constitute the first block. A block switch 105 and a constant current circuit 106 are provided for each block. When the block switch 105 is turned on, a voltage can be applied to the plurality of LEDs 80 belonging to the block. A plurality of LEDs 80 in each column is provided with a column switch 107 that bypasses the LED 80 for each block, and a group of illumination LEDs 80 is connected in series with the column switch 107 in parallel. In FIG. 35, only one illumination LED 80 for each circumferential row is shown, but this is only for simplifying the diagram, and for illumination connected in parallel with each row switch 107. It should be understood that there are a plurality of LEDs 80 in series.

  Each column belonging to each block is connected in series, and the column switch 107 described above is connected in parallel to each column.

  Therefore, by turning off an arbitrary column switch 107, a constant current is supplied to a plurality of LEDs 80 belonging to the corresponding block and the corresponding column. By providing this LED drive circuit in the external illumination unit 4A, it is possible to arbitrarily set the area of partial illumination for each column of each block.

  Moreover, by providing the constant current circuit 106 for each block, for example, the current flowing through the illumination LEDs 80 in the first to third circumferential rows in the same block can be maintained constant. In other words, without the constant current circuit 106, for example, when the illumination LEDs 80 in the second and third circumferential rows are lit, the illumination LEDs 80 in the first circumferential row are switched from OFF to ON. The voltage applied to the illumination LEDs 80 in the third circumferential row changes, the current flowing through the second and third illumination LEDs 80 changes, and the brightness changes.

  In other words, even if the block switch 105 is turned ON / OFF, the light emission amount of the illumination LED 80 belonging to another block does not change. This is because each block is connected to the power supply in parallel with each other. However, when the column switch 107 is turned ON / OFF, the number of LEDs 80 lit in the block changes, and the brightness of the LEDs 80 changes accordingly.

  This means that, when setting the lighting pattern of partial illumination, it is desirable to eliminate as much as possible the factors that change the brightness of the LED 80 in order to find out how to best apply light to the workpiece. The constant current circuit 105 is provided in each block for this purpose. Thereby, when setting the lighting pattern, the optimal lighting pattern is ensured by uniformizing the luminance of the LED 80 in the lighting area for partial illumination when the lighting pattern is changed and ensuring the uniformity of the luminance. It will be easier to find. In addition, the LED drive circuit of FIG. 35 can be similarly adopted for the large-diameter external illumination unit 4B and the internal illumination unit 4B.

Partial illumination of the internal illumination unit 5 and the external illumination unit 4 (FIG. 36) :
The internal lighting unit 5 and the external lighting unit 4 are both surface light sources, but the surface light source can be divided into several areas in the circumferential direction and the radial direction, and partial illumination can be performed in units of each area. The user can arbitrarily set the lighting pattern of which area is lit and which area is not lit. The lighting pattern including lighting of all areas can be registered in advance by the user using the PC 3, and the lighting pattern set by the user is obtained when the memory M of the barcode reader 2 and the external lighting unit 4 are connected. This is stored in the memory M of the external illumination unit 4. This lighting control includes control of the light emission amount of the illumination LED 80. 36, only one LED 80 for illumination in each circumferential row is shown in the same manner as in FIG. 35 described above. However, this is merely a reason for simplifying the diagram, and each row switch 107 is shown in FIG. It should be understood that there are a plurality of lighting LEDs 80 connected in parallel with each other.

  As described with reference to FIG. 1, the external illumination unit 4 includes CPU control means. Therefore, as shown in FIG. 36, the partial illumination areas divided in the circumferential direction and the radial direction are set by controlling each block switch 105 and the column switch 107 of each circumferential row by the CPU of the external illumination unit 4. Sometimes, the lighting control of the LED 80 is executed in units of this area.

Details of the switch mechanism (Fig. 37) :
FIG. 37 shows details of the block switch 105 and column switch 107 seen in FIGS. As can be seen from FIG. 37, the block switch 105 and the column switch 107 employ a transistor 109 as a switch element. Although not shown in FIG. 37, it should be understood that the constant current circuit 106 is incorporated in each block even in the LED drive circuit.

  As a modification, a switch is provided in each of the plurality of illumination LEDs 80 belonging to each block, and the switch can be controlled to light up for each arbitrary area. As another modification, the current value of the constant current circuit 106 may be controlled. Specifically, the number of lighting LEDs 80 in each block changes depending on ON / OFF switching of the column switch 107. And if the number of lighting of LED80 for illumination changes, the brightness as the whole of the external illumination unit 4 or the internal illumination unit 5 will change. In order to suppress this change in brightness, the current value of the constant current circuit 106 is changed in response to ON / OFF of the column switch 107 so that the overall brightness of the external lighting unit 4 and the internal lighting unit 5 is improved. It is good to control so that it may become equal. For example, when the outer peripheral side column switch 107 is turned ON and the inner peripheral side column switch 107 is turned OFF to turn off the inner peripheral side illumination LED 80, the outer peripheral side LED 80 is turned off to the outer peripheral side. You may control so that the brightness of LED80 for illumination may become large.

  As a further modification, the current value of the constant current circuit 106 may be changed in response to ON / OFF switching of the block switch 105 as well as the column switch 107. The control of the brightness of the LED 80 in response to the switching of the block switch 105 is performed so that the brightness of the lighting LED 80 increases as the number of blocks to be lit decreases, and conversely, as the number of blocks to be lit increases. The overall brightness of the external lighting unit 4 and the internal lighting unit 5 may be controlled to be equal by controlling the brightness of the lighting LED 80 to be small. The brightness of the lighting LED 80 can be controlled by changing the current value of the constant current circuit 106 as described above.

  Here, in the circuits shown in FIGS. 35 and 36 of the embodiment, the same constant current circuit 106 is provided in each block circuit, and the value of the current flowing through each block is controlled to be a predetermined current value. It should be noted. According to this circuit, local light and darkness in which the LEDs 80 in one area are bright and the LEDs 80 in other areas are relatively dark does not occur. In addition to this, when the brightness is controlled to vary depending on the number of columns to be lit and the number of blocks, the brightness of all the lit LEDs 80 is changed simultaneously by the constant current circuit 106. The brightness of each area is the same.

Lighting control areas of the external lighting unit 4 and the internal lighting unit 5 (FIGS. 38 and 39) :
As described above, the external lighting unit 4 and the internal lighting unit 5 can be partially lit. The block switch 105 and the column switch 107 described above will be described in detail with reference to FIGS. 38 and 39. As can be seen from FIG. 38, the term “block” is an area obtained by dividing a ring-shaped surface light source in the circumferential direction. I mean. Next, the term “column” means the illumination LEDs 80 belonging to a common concentric circle among the illumination LEDs 80 belonging to each block. Therefore, referring to FIG. 38, the first column of the first block means a group of illumination LEDs 80 located on the outermost periphery among the plurality of illumination LEDs 80 belonging to “Block 1”.

  As described above, power supply to the plurality of illumination LEDs 80 belonging to each block is first controlled by the block switch 105. On the premise of this, power supply to the plurality of illumination LEDs 80 belonging to each column is controlled by the column switch 107. Therefore, to turn on the LED 80 in the first column of the first block as described above, it is realized by turning on the column switch 107 in the first column on the assumption that the block switch 105 in the first block is ON. it can.

  Regarding “column”, for example, “column 2” and “column 3” illustrated in FIG. 38 may be handled as one column. That is, a plurality of columns belonging to the same block may be handled as one column.

  In the partial lighting control described above, for example, in order to set one partial lighting area in the second row and the third row of the first block, the second block is based on the assumption that the block switch 105 of the first block is ON. This can be realized by turning on both the two column switches 107 of the column and the third column. Accordingly, as described above, the switches 105 and 107 are provided for each block divided in the circumferential direction and for each column belonging to each block, and the partial lighting areas of the external lighting unit 4 and the internal lighting unit 5 can be freely set by combining them. Can be set to

  Further, as described above, in the driving circuit of the illumination LED 80, the constant current circuit 106 is incorporated for each block (FIG. 35), and preferably, the constant current circuit 106 is further incorporated for each column (FIG. 36). ). With this constant current circuit 106, the luminance of the surface light source produced in each area can be maintained uniformly throughout the entire area.

  FIG. 40 is a diagram schematically showing an overview of the barcode reader system 1 described in the block diagram in FIG. The barcode reader 2 is provided with a main circuit 10 and a power supply circuit 11 on which a CPU is mounted adjacent to and along the side surface of the outer case. The camera module 32 is positioned so as to be sandwiched between the main circuit 10 and the power supply circuit 11. The camera module 32 includes a pointer LED 40, and the light beam of the pointer LED 40 is configured to pass through the imaging lens assembly 36. A ring-shaped internal illumination unit 14 is disposed around the lens assembly 36, and the illumination LEDs 80 are mounted almost uniformly over the entire circumference of the ring-shaped LED substrate 14. ing. Further, as additional external illumination, illumination LEDs 80 of the ring-shaped external illumination unit 4 are arranged in a ring shape around the optical axis of the lens assembly 36, and this ring-like arrangement is at least two radially spaced apart. A group of illumination LEDs 80 in a row is configured.

  A person skilled in the art will be able to understand the following immediately by looking at FIG. That is, the barcode reader 2 has a simple configuration and is excellent in heat countermeasures and is compact, and further, has a large number of rings positioned at high density around the optical axis of the lens assembly 36 of the barcode reader 2. It is possible to freely set partial illumination with respect to the illumination LED 80. Furthermore, since the external illumination unit 4 includes a control means (CPU), the illumination LED 80 of the external illumination unit 4 can be controlled only by the communication between the barcode reader 2 and the external illumination unit 4, Excellent responsiveness can be realized with respect to blinking of the LED 80 for illumination.

  It is applied to illumination when reading optical information such as bar codes and QR codes.

1 Bar code reader system 2 Bar code reader (optical information reader)
3 Personal computer (PC)
4 External Lighting Unit 5 Internal Lighting Unit Built in Barcode Reader 10 Barcode Reader Main Board M Memory Mounted on Main Board 13 CMOS Board (Light-Receiving Board)
14 LED substrate 32 Camera module 36 Lens assembly 43 Optical reader (imaging device: CMOS)
77 LED board for external illumination unit 78 Circuit board for external illumination unit 80 LED for illumination
105 block switch 106 constant current circuit 107 column switch 109 transistor as switching element

Claims (4)

An LED illumination device that is used in an optical information reading device that reads optical information from a work provided with optical information, and in which illumination LEDs are arranged in a ring shape around the optical axis of the optical information reading device,
A plurality of lighting LEDs in a first row arranged on a first circumference;
A plurality of illumination LEDs in a second row arranged on a second circumference having a diameter different from the first circumference;
A plurality of illumination LEDs belonging to each block are connected in series for each block obtained by dividing the first row and the second row in the circumferential direction, and a plurality of blocks belonging to the block are turned ON / OFF. A block circuit for generating a state in which a voltage can be applied to the illumination LED
A constant current circuit connected to each block circuit;
A plurality of lighting LEDs connected in series to each block circuit is divided into the first and second columns, and a column switch connected in parallel with the lighting LEDs in each column,
LED lighting for an optical information reading device, wherein partial illumination can be performed with a lighting pattern set by a user for each preset area by controlling ON / OFF of the block switch and the column switch apparatus. The LED illumination device is an external illumination unit connectable to the optical information reader;
The LED illumination device for an optical information reading device according to claim 1, wherein the external illumination unit includes control means for controlling ON / OFF of the block switch and the column switch. The LED lighting device further includes a memory that stores the lighting pattern set by a user,
The LED for an optical information reading device according to claim 2, wherein lighting of the plurality of lighting LEDs is controlled according to the lighting pattern stored in a memory of the LED lighting device by communication with the optical information reading device. Lighting device. The LED lighting device includes an LED board on which the plurality of LEDs are mounted, and a circuit board including a drive circuit for driving the plurality of LEDs.
The LED board and the circuit board are stacked up and down via a spacer,
The LED substrate has a ring-shaped shape that is substantially the same size as the ring-shaped cross-sectional shape of the outer case of the LED lighting device;
The LED illumination device for an optical information reader according to claim 3, wherein the control unit is mounted on the circuit board.

Images