Photoelectric switch and sensor unit

Abstract

To provide a connection structure of a signal cable which can secure a sufficient display area of a display in a photoelectric switch.SOLUTION: A photoelectric switch has a housing having a substantially rectangular parallelepiped shape. A display 5 is provided on a first surface of the housing and has a display area. A signal cable 51 connects a control board with the display 5. The display 5 has a connection part 70a connected with the signal cable 51. The connection part 70a is disposed between the display area and the signal cable in a longitudinal direction of the housing. The structure provides a connection structure of the signal cable 51 which can secure a sufficient display area of the display 5 in the photoelectric switch.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a photoelectric switch and a sensor unit. [Background technology]

[0002] Products (workpieces) produced in a factory are transported by a transport device such as a belt conveyor, and their arrival at a predetermined location is detected by a photoelectric switch. A photoelectric switch generally projects light toward a workpiece or the like, receives the light reflected from the workpiece, and displays a numerical value indicating the amount of received light and a threshold value with which this numerical value is compared on a seven-segment display (Patent Document 1). When the photoelectric switch detects a workpiece based on the amount of received light and the threshold value, it outputs an ON signal indicating detection. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-141961 A Summary of the Invention [Problem to be solved by the invention]

[0004] Thus, a photoelectric switch is a relatively simple sensor that outputs a detection signal indicating whether or not a workpiece is detected. For this reason, seven-segment displays have been used as indicators for many years. Photoelectric switches that do not have an indicator that displays numerical values ​​still exist. However, in recent years, as photoelectric switches have become more advanced, seven-segment displays are no longer able to provide sufficient information to users. Therefore, the inventor of the present application considered adopting a dot-matrix indicator such as an OLED (organic light-emitting diode). A dot-matrix display has many wires (gate lines, signal lines, power lines, and ground lines), and displays information by turning on / off semiconductor switches arranged at the intersections of these. The many wires are connected to a controller via an FPC cable. The problem here is the shape of the housing of the photoelectric switch. In a factory, many photoelectric switches are connected to a DIN (German Institute for Standardization) rail, so the shape of the photoelectric switch is a long and narrow, approximately rectangular parallelepiped. Therefore, the top surface of the photoelectric switch on which the indicator is attached is also long and narrow. This limits the length of the short side of the indicator. As mentioned above, dot matrix displays have a large number of wires, so unless the connection positions of these and the FPC (flexible printed circuit) cable are carefully considered, it is difficult to ensure a sufficient display area.

[0005] SUMMARY OF THE PRESENT EMBODIMENTS An object of the present invention is to provide a signal cable connection structure that can ensure a sufficient display area for a display in a photoelectric switch. [Means for solving the problem]

[0006] The present invention relates to, for example, A detection unit for detecting a physical quantity from a detection target; a dot matrix display for displaying a physical quantity of the detection target detected by the detection unit; The physical quantity To an adjustment button for adjusting the threshold for The threshold value adjusted via the adjustment button; The physical quantity of the detection target detected by the detection unit before Note Dot matrix display area The controller to be displayed and , an indicator light that outputs a comparison result between the physical quantity detected by the detection unit and a threshold value; The above indicator light of The first board on which the LEDs are mounted and of Preparation, The indicator light and the Dot Matrix Display and the adjustment button 、 The above Dot Matrix Display In the longitudinal direction of Along the lines of the indicator lamp, the dot matrix display, and the adjustment button, Arranged, The above Dot Matrix Display of The display area is The indicator light is offset toward the indicator light in the longitudinal direction. The above Dot Matrix Display To The terminal of the signal line for display is The adjustment button side in the longitudinal direction To be established The present invention provides a sensor unit having a structure comprising: Effect of the Invention

[0007] According to the present invention, there is provided a signal cable connection structure that can ensure a sufficient display area for a display in a photoelectric switch. [Brief description of the drawings]

[0008] [Figure 1] A perspective view showing a photoelectric switch [Diagram 2] FIG. 1 is a perspective view showing a plurality of photoelectric switches connected together; [Diagram 3] Explosion diagram showing a photoelectric switch [Figure 4] A perspective view showing a photoelectric switch [Diagram 5] FIG. 2 is a perspective view showing the positional relationship between a cover member, a display unit, and a shield member; [Figure 6] Diagram explaining the upper case, etc. [Figure 7] Diagram explaining the relationship between the display and the signal cable [Figure 8] Diagram explaining the position of the slits [Figure 9] Diagram explaining the position of the slits [Figure 10] FIG. 1 shows an integrated signal cable and shielding member. [Figure 11] Diagram explaining the relationship between the display and the signal cable [Figure 12] Cross-section of a photoelectric switch [Figure 13] Enlarged cross-section of a photoelectric switch DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] An embodiment of the present invention will be described below. The individual embodiments described below will be useful for understanding various concepts, such as higher-level concepts, middle-level concepts, and lower-level concepts, of the present invention. The technical scope of the present invention is determined by the claims, and is not limited by the individual embodiments described below.

[0010] FIG. 1 is a perspective view showing a photoelectric switch. The photoelectric switch 1 has a substantially rectangular housing. Here, the z-axis corresponds to the longitudinal direction. The x-axis corresponds to the lateral direction. The y-axis corresponds to the height direction. The housing has approximately six outer surfaces. The six outer surfaces include a top surface, a bottom surface, a front surface, a rear surface, a left side surface, and a right side surface. In FIG. 1, the top surface, the front surface, and the right side surface are visible. The housing has a lower case 2 and an upper case 3. By fitting the lower case 2 and the upper case 3 together, an internal space is formed in which a control board and the like are accommodated. A part of the upper case 3 forms the upper surface. On the upper surface, a display 5, a mode button 7, an active receiver button 8, an adjustment button 9, a slide switch 10, a set button 11, an indicator light 24, a clamp module 14, and the like are provided. The display 5 is a dot matrix display such as an OLED, and displays a threshold value, an amount of received light, and the like. The display 5 is sandwiched and fixed between the outer surface of the upper case 3 and a cover member 4. The display 5 is provided offset toward the front side from the center of the top surface. The adjustment button 9 is a button for increasing or decreasing the threshold value or operating the menu. The menu is a menu that is displayed on the display 5 and has various setting items for setting the operation of the photoelectric switch 1. The mode button 7 is a button for switching the operation mode related to the amount of light emitted, etc. The active receiver button 8 is a special button for emitting light from the photoelectric switch 1 to the outside through the receiving optical fiber. When the photoelectric switch 1 detects the depression of the active receiver button 8, it uses the receiving optical fiber as the projecting optical fiber as well, and receives light incident from the outside while projecting light toward the outside. This light is not light for detecting the workpiece, but light for assisting the user in adjusting the optical axis. The light-emitting element that outputs the assist light may be disposed, for example, in the center of the light-receiving element. In this case, the light-receiving surface of the light-receiving element is larger than the light-emitting surface of the light-emitting element. The slide switch 10 is a switch for selecting a set of setting parameters from among a plurality of sets. The set button 11 is a button for starting automatic setting of the threshold value. When the photoelectric switch 1 detects that the set button 11 has been pressed, it determines the threshold value according to the amount of received light. The indicator light 24 turns on or off, for example, when a workpiece is detected.The clamp module 14 is a module that clamps and holds the light emitting fiber and the light receiving fiber. A cylindrical hole 12 into which the light emitting fiber is inserted and a cylindrical hole 13 into which the light receiving fiber is inserted are provided on the front surface of the housing. An output cable is attached to the rear surface of the housing. A cable bush 15 is a bush for holding the output cable.

[0011] A connector 16a and connecting parts 17a and 17b are provided on the right side of the housing. FIG. 2(A) shows that a plurality of photoelectric switches 1 are connected to each other by the connector 16a and connecting parts 17a and 17b, respectively, and fixed to a DIN rail 18. DIN is an abbreviation for the German Institute for Standardization. The incident end of the light-emitting fiber 22 is inserted into the hole 12, and the emission end of the light-receiving fiber 23 is inserted into the hole 13. FIG. 2(A) also shows an openable and closable upper cover 19 that covers the upper surface of the housing. Note that, as shown in FIG. 2(B), if the upper cover 19 is translucent, the upper surface of the upper cover 19 does not need to have a hole. This is because, if the upper cover 19 is translucent, the user can check the display content of the display unit 5 even when the upper cover 19 is closed. If the upper cover 19 is not translucent, a hole or a window may be provided in the upper surface of the upper cover 19, as shown in FIG. 2(A). The upper cover 19 functions as a dust cover. As shown in Figures 2(A) and 2(B), a plurality of photoelectric switches 1 can be connected to each other laterally, and therefore are also called a linked sensor.

[0012] FIG. 3 is an exploded view of the photoelectric switch 1. A decorative member 20 may be provided on the rear end side of the upper cover 19. A pivot pin 19a is provided on the rear end side of the upper cover 19. The pivot pin 19a fits into a holding hole 19b provided on the rear end side of the upper case 3. This allows the upper cover 19 to be pivotally connected to the upper case 3. The upper cover 19 may be formed of a transparent member so that the user can check the information displayed on the display 5 even when the upper cover 19 is closed. A spine member 36 for supporting the display 5 is provided near the center of the upper case 3. Four fringes 47 are provided on the left and right sides of the spine member 36. The four fringes 47 are protrusions that protrude upward from the upper case 3 and position the display 5 in the short side direction (x direction). The four fringes 47 fit into recesses in the cover member 4. In addition, two claws 48 are provided on the left and right sides of the spine member 36. The claw portion 48 fits into a recess provided on the inside of the central leg of the cover member, and fixes the cover member 4 to the upper case 3. The recess may be a groove or a through hole. An opening 25 is provided on the rear end side of the display mounting portion centered on the backbone member 36. The opening 25 is a through hole or a notch for passing a signal cable from the outer surface to the inner surface of the upper case 3. The signal cable includes a power line that supplies power to the display 5 and a control line that supplies a control signal. The signal cable is connected to the control board 30. Here, the control board 30 may be a single board. If two boards are provided in the x-axis direction, the length of the photoelectric switch 1 in the x-axis direction will be long. Therefore, in this embodiment, only one control board 30 is provided in the x-axis direction. The control board 30 is equipped with a controller 6 such as a CPU (Central Processing Unit). The controller 6 displays the threshold value and the amount of received light on the display 5. The control board 30 is equipped with switches corresponding to the adjustment button 9, the mode button 7, the active receiver button 8, the slide switch 10, and the set button 11. These buttons may be made of resin such as POM (polyacetal), etc. The upper cover 19, the cover member 4, and the housing may basically be made of polycarbonate.In addition, LEDs (light emitting diodes) that supply light to the light diffusing member of the indicator lamp 24 are also mounted on the control board 30. The control board 30 is provided with a connector 16a for communicating with another adjacent photoelectric switch 1 and for receiving power. An element holder 26 is provided on the front side of the control board 30, and a light emitting element 32 and a light receiving element 33 are attached to the element holder 26. The element holder 26 has a hole for the light emitting fiber 22 inserted from the hole 12 and a hole for the light receiving fiber 23 inserted from the hole 13. A clamp module 14 is disposed on the front side of the element holder 26 and holds the light emitting fiber 22 and the light receiving fiber 23. A fixture 28 for fixing to the DIN rail 18 and a metal cover 29 are attached to the bottom surface of the lower case 2. The metal cover 29 may serve as a heat dissipation and electromagnetic shield.

[0013] Fig. 4(A) is a perspective view of the photoelectric switch 1 in a state in which the cover member 4 is fixed to the upper case 3. Fig. 4(B) is a perspective view of the photoelectric switch 1 in a state in which the cover member 4 is not fixed to the upper case 3. Here, various buttons and indicators 5 are fixed to the upper case 3, and further, a control board 30 is also fixed to the upper case 3. A signal cable 51 electrically connecting the indicator 5 and the control board 30 passes through the opening 25 and enters the inside of the housing, and is connected to a connector of the control board 30. A connector 16b is provided on the left side surface of the control board 30. The connector 16b of the photoelectric switch 1 is a female connector, and is fitted with a male connector 16a of another photoelectric switch 1 located to the left of the photoelectric switch 1, for electrical connection.

[0014] As can be seen from Figure 4(A) and other figures, the height of the active receiver button 8 is lower than the height of the mode button 7 and the adjustment button 9. This is to prevent the active receiver button 8 from being operated accidentally.

[0015] FIG. 5 is a perspective view for explaining the cover member 4 in detail. The cover member 4 has two front legs 42, two central legs 43, and two rear legs 44. A window portion 40 is provided on the upper surface of the cover member 4. A user can see the display surface of the display device 5 through the window portion 40. The window portion 40 is surrounded by four frames. The left frame 41a and the right frame 41b are thinner than the front frame 41d and the rear frame 41c. This is to ensure the display area in the short side direction of the photoelectric switch 1. The rear frame 41c has a larger area than the other frames. This is because the rear frame 41c protects the IC that controls the display device 5. Character information, etc. may be printed on the rear frame 41c. In addition, since the rear frame 41c has a certain area, even if the user presses the adjustment button 9 with his / her finger, the display information of the display device 5 is unlikely to be hidden by the finger. In other words, the rear frame 41 can sufficiently separate the distance between the display device 5 and the button. In addition, since the area of ​​the front frame 41 is small, the indicator lamp 24 and the display device 5 can be placed close to each other. This allows the information transmission mechanism that attracts the user's attention to be concentrated in one place. A total of four notches 46 are provided on the right and left sides of the cover member 4. The four notches 46 fit into four fringes 47 provided on the upper case 3 to position and fix the cover member 4 relative to the upper case 3. Recesses 45 are provided on the inner surfaces of the two center legs 43. The recesses 45 fit into claws 48 provided on the right and left sides of the upper case 3. A shield member 50 may be used to protect the front, bottom, left and right sides of the display 5. The shield member 50 has a front wall 50d that protects the front of the display 5, a bottom 50a that protects the bottom of the display 5, a right wall 50b that protects the right side of the display 5, and a left wall 50c that protects the left side of the display 5. The display 5 is sandwiched between the spine member 36 and the cover member 4 while covered by the shield member 50. The shielding member 50 may be formed of an FPC (flexible printed circuit board).

[0016] Fig. 6(A) is a plan view showing the top surface of the photoelectric switch 1. As shown in Fig. 6(A), no switches or buttons are provided in the short-side direction of the display unit 5. Therefore, the dimension of the display unit 5 in the short-side direction can be made sufficiently large. The rear frame of the cover member 4 has an area large enough to allow printing of characters, etc.

[0017] Fig. 6(B) shows the left side of the upper case 3. Fig. 6(C) shows the left side of the upper case 3 with the control board 30 attached. A terminal 52 of a signal cable 51 extending from the display 5 is connected to and fixed in a connector 16c mounted on the control board 30. The signal cable 51 enters from the outside of the housing to the inside and is connected to the control board 30, and is therefore formed of a thin and flexible FPC cable or the like.

[0018] Fig. 6(D) shows the photoelectric switch 1 with the lower case 2 attached. Fixing holes 63a, 63b are provided on the left side surface of the lower case 2. Linking portions 17a, 17b of another photoelectric switch 1 located adjacent to the left are inserted into the fixing holes 63a, 63b of the photoelectric switch 1, respectively. Note that a hole is provided on the left side surface of the lower case 2 through which the connector 16b is exposed, but in Fig. 6(D) the hole is protected by a lid 64.

[0019] <Signal cable layout for display unit> FIG. 7(A) shows the right side of the display 5. The display 5 is formed by stacking a transparent member 70, an OLED layer 71, and a transparent base material 72 in the height direction. The transparent member 70 and the transparent base material 72 are made of a transparent substrate (second substrate) containing glass, resin, or the like. A transparent electrode extending from the long side of the OLED layer 71 and a transparent electrode extending from the short side are formed on the bottom surface of the transparent member 70 and are electrically connected to the driving IC 54. The driving IC 54 is an integrated circuit that drives the display 5. The driving IC 54 is fixed to the bottom surface of the transparent member 70 by an adhesive 73. A signal cable 51 extending from the control board 30 is electrically connected to the terminal of the driving IC 54. In this way, the signal cable 51 is connected to the end of the longitudinal direction of the display 5, that is, to the terminal (connection portion 70a) provided on the short side of the display 5. This makes it easier to ensure the display area in the short direction of the display 5. At workpiece manufacturing and inspection sites, a plurality of photoelectric switches 1 are connected for use. For this reason, the length of the short side of the photoelectric switch 1 is set to, for example, 5 mm or more and 14 mm or less. If the driving IC 54 and the signal cable 51 are attached to the short side of the display 5, the display area of ​​the display 5 will be narrowed. In other words, the characters displayed on the display 5 will become difficult to read. For this reason, it is preferable that the driving IC 54 and the signal cable 51 are not attached to the end (long side) of the short side of the display 5.

[0020] 7(B) shows that a driving IC 54 is provided midway along the signal cable 51. This will help to shorten the longitudinal length of the transparent member 70. The transparent electrodes extending from the long sides of the OLED layer 71 are connected to the signal cable 51 as terminals (connection parts 70a) provided on the short sides of the display 5.

[0021] FIG. 7(C) shows that the backbone member 36 of the upper case 3 is used as the base material instead of the transparent base material 72. This helps to make the display 5 thinner. In other words, it helps to reduce the height of the display 5. The backbone member 36 has an opening 25, and the signal cable 51 passes through the opening 25 to enter the inside of the housing. The driving IC 54 is disposed in the middle of the signal cable 51 and is located inside the housing. The transparent electrode extending from the long side of the OLED layer 71 and provided on the transparent member 70 is connected to the signal cable 51 as a terminal (connection portion 70a) provided on the short side of the display 5.

[0022] Thus, the display 5 has the OLED layer 71 that functions as a display layer, and the transparent member 70. The transparent electrode functions as a signal line extending from the OLED layer 71 to the signal cable 51. The transparent electrode is provided near the interface between the OLED layer 71 and the transparent member 70. The cover member 4 covers the side surface near the interface between the OLED layer 71 and the transparent member 70. Since the area near this interface is easily damaged, the cover member 4 protects the area near the interface.

[0023] <Cable passage arrangement> FIG. 8(A) shows a schematic cross-sectional view of the upper case 3. FIG. 8(B) to FIG. 8(E) show perspective views of the display mounting portion. The upper case 3 includes a first upper surface 38 on which the set button 11 is arranged, a second upper surface (front wall 37), a third upper surface (backbone member 36), a fourth upper surface (rear wall 35), and a sixth upper surface 34 on which the adjustment buttons 9 and the like are arranged. The first upper surface 38 and the sixth upper surface 34 may be called the upper stage, and the backbone member 36 may be called the lower stage. In this way, the upper surface of the upper case 3 may have a step. The backbone member 36 may be called a mounting portion. The mounting portion may be solid from the viewpoint of improving rigidity. As shown in FIG. 8(A), the second upper surface (front wall 37), the third upper surface (backbone member 36), and the fourth upper surface (rear wall 35) form a recess in a cross section along the longitudinal direction of the housing. The display 5 is pressed against the wall surface (front wall 37) closer to the second surface out of the two wall surfaces forming the recess. According to FIG. 8(A) and FIG. 8(B), the opening 25 is a slit-shaped hole provided on the rear end side of the backbone member 36. This suggests that the opening 25 may be provided on the front end side of the backbone member 36. According to FIG. 8(C), the opening 25 is provided on the lower side of the rear wall 35. This suggests that the opening 25 may be provided on the lower side of the front wall 37. The opening 25 may be provided at the connection part between the backbone member 36 and the rear wall 35 (front wall 37). In other words, a slit may be formed across the backbone member 36 and the rear wall 35 (front wall 37). FIG. 8(D) shows that the opening 25 is provided in the center of the backbone member 36. Here, the area of ​​the opening 25 is basically smaller than the bottom area of ​​the display 5. This is because the bottom surface of the display 5 is supported by the backbone member 36. However, it is sufficient that the bottom surface of the display 5 is supported by either two long frames extending in the longitudinal direction of the spine member 36 or two short frames extending in the lateral direction of the spine member 36. FIG. 8(E) shows that the notched opening 25 is provided on the right side of the spine member 36. This suggests that the notched opening 25 may be provided on the left side of the spine member 36. If the signal cable 51 is a highly flexible and bendable cable such as an FPC cable, the degree of freedom in arranging the opening 25 will increase. Note that the case of FIG. 8(E) will mainly be a case in which the signal cable 51 is connected to the long side of the display 5.However, if the signal cable 51 is an FPC cable, it may be possible to pass the signal cable 51 extending from the short side of the display 5 through the notch-shaped opening 25 shown in FIG. 8(E).

[0024] FIG. 9(A) shows the opening 25 provided at the rear end of the spine member 36. As FIG. 9(A) shows, the housing of the photoelectric switch 1 is long and thin. Focusing on the spine member 36, it can be seen that the display mounting portion is present up to the edge of the housing. This helps to enlarge the display area of ​​the display 5. The fact that the opening 25 is provided on the rear end side of the spine member 36 also helps to enlarge the display area of ​​the display 5. FIG. 9(B) shows the signal cable 51 bent in order to pass through the opening 25. In this way, the signal cable 51 extends from the outside to the inside of the upper case 3 through the opening 25.

[0025] <Integrated shielding of signal cables> FIG. 10 shows a signal cable 51 made of an FPC 60. Here, a display module including a display 5 and a driving IC 54 is also shown together with the signal cable 51. The signal cable 51 is integrated by the shielding member 50 and the FPC 60. The shielding member 50 has a metal layer such as copper and a base film layer. The right wall 50b is formed by folding the FPC 60 at a right angle at the crease 56c. The left wall 50c is formed by folding the FPC 60 at a right angle at the crease 56d. The front wall 50d is formed by folding the FPC 60 at a right angle at the crease 56e. In order to make it easier to fold the FPC 60, a plurality of holes 55 may be provided in the metal layer along the creases 56c, 56d, and 56e. The metal layer is connected to the ground line of the signal cable 51. This allows the shielding member 50 to protect the OLED (display 5) from electrical noise.

[0026] Furthermore, by folding the FPC 60 at a right angle along the fold 56a, the shielding member 50 covers the bottom surface of the display 5. The U-shaped folded portion of the signal cable 51 shown in FIG. 9B is formed by overlapping the signal wiring portion 53a and the shield wiring portion 53b of the FPC 60. That is, by folding the FPC 60 at a right angle along the fold 56a, the signal wiring portion 53a and the shield wiring portion 53b overlap. Furthermore, when the FPC 60 is inserted through the opening 25, the overlapping portion of the signal wiring portion 53a and the shield wiring portion 53b is folded at a right angle. Furthermore, by folding the FPC 60 at a right angle along the fold 56b, the mounting surface of the terminal 52 becomes parallel to the control board 30.

[0027] 11(A) to 11(E) show the positional relationship between the display 5 and the signal cable 51. FIG. 11(A) is a plan view of the display 5 to which the signal cable 51 is connected. FIG. 11(B) is a view showing the left side of the display 5. The signal cable 51 extending from the rear end side of the display 5 is bent into a U shape at an overlapping portion 53 formed by overlapping the signal wiring portion 53a and the shield wiring portion 53b. Furthermore, by bending the signal cable 51 at a right angle at the fold 56b, the mounting surface of the terminal 52 becomes parallel to the control board 30. FIG. 11(C) to 11(E) are perspective views of the display 5. The mounting surface of the terminal 52 becomes parallel to the control board 30, but is perpendicular to the bottom surface of the display 5.

[0028] The terminal 52 may be composed of, for example, eight pins. The VCC pin is a pin that supplies power to the driving IC 54. The VSS pin is a pin that is connected to ground (provides a ground potential). The RES pin is a pin that supplies a reset signal to the driving IC 54 for starting or restarting the driving IC 54. The SCLK pin is a pin that supplies a clock for serial communication. The SDA pin is a pin that transmits data for serial communication. The IREF pin is a pin that adjusts the current flowing through the OLED layer 71. The VCOMH pin is a pin that connects an external capacitor to the driving IC 54 in order to stabilize the internal power supply of the driving IC 54. The VDD pin is a pin that supplies a voltage for the logic operation of the driving IC 54.

[0029] The shielding member 50 may be a shielding sheet formed of a separate material from the signal cable 51 .

[0030] <Shield> FIG. 12(A) is an AA cross-sectional view obtained by cutting the photoelectric switch 1 along the AA cutting line in FIG. 6(D). FIG. 12(B) is a BB cross-sectional view obtained by cutting the photoelectric switch 1 along the BB cutting line in FIG. 6(D). FIG. 13 is an enlarged view of a part of FIG. 12(A). As shown in FIG. 12(A) and FIG. 13, the claws 48 of the upper case 3 are fitted into the recesses 45 provided in the left and right central legs 43 of the cover member 4. As shown in FIG. 12(A), FIG. 12(B), and FIG. 13, the heights of the right wall 50b and the left wall 50c of the shield member 50 are such that they cover the OLED layer 71 and the transparent base material 72 of the display 5, respectively, and cover at least a part of the transparent member 70. The transparent member 70 and the transparent base material 72 are made of glass or the like. Glass is more easily broken than resin. Therefore, the shield member 50 protects the transparent member 70 and the transparent base material 72 from impacts and the like. The OLED layer 71 is also protected from electrical noise by the shielding member 50. The bottom surface of the display 5 is covered by a bottom part 50a of the shielding member 50. The backbone member 36 makes it difficult for heat generated from the control board 30 to be transmitted to the display 5.

[0031] 12(B), the tips of the left and right front legs 42 of the cover member 4 are clamped between the lower case 2 and the upper case 3. This allows the cover member 4 to be firmly fixed to the housing.

[0032] <Summary> As described with reference to FIG. 1 and the like, the photoelectric switch 1 has a housing having a substantially rectangular parallelepiped shape. In other words, the housing is long and narrow. The display 5 is an example of a display unit attached to the first surface of the housing. Conventionally, the display was housed inside the housing of the photoelectric switch, so there was a distance between the outer surface of the housing and the display, making it difficult to see the displayed information. In this embodiment, the display 5 is attached to the outer surface of the housing, so the distance from the outer edge of the photoelectric switch 1 to the display 5 is shortened, making it easier to see the displayed information on the display 5. The light-emitting element 32 and the hole 12 are an example of a light-projecting unit provided near the second surface located next to the first surface. The light-receiving element 33 and the hole 13 are an example of a light-receiving unit provided near the second surface located next to the first surface. The adjustment button 9 and the like are an example of a receiving unit provided on the first surface or the display unit and receiving a user operation. The controller 6 is an example of a display control unit that causes the display unit to display the threshold value adjusted through the receiving unit and a signal value indicating the amount of light received by the light-receiving unit. The control board 30 is housed inside the housing, and is an example of a control board (first board) on which a display control unit is mounted or connected. The signal cable 51 is an example of a signal cable that connects the control board 30 and the display 5. As shown in Figs. 6(A) to 6(C), the display 5 has a connection part that is connected to the signal cable 51. The connection part of the display 5 is disposed between the display area and the signal cable 51 in the longitudinal direction of the housing. As shown in Figs. 7(A) to 7(C) and 10, the display 5 may have two short sides and two long sides, and the signal cable 51 may be connected to one of the two short sides. This provides a connection structure for the signal cable 51 that can ensure a sufficient display area for the display 5 in the photoelectric switch 1.

[0033] The display unit may have a dot matrix display and a driving circuit for driving the dot matrix display. The display 5 is an example of a dot matrix display. The driving IC 54 is an example of a driving circuit. As shown in FIG. 7(A) and the like, the driving IC 54 is provided at an end of the display 5 in the longitudinal direction, and a signal cable 51 is connected to the driving IC 54. That is, the driving IC 54 may be provided between the display 5 and the connection part in the longitudinal direction of the housing. The display 5 and the driving IC 54 may be disposed on the same member. According to FIG. 7(A), the OLED layer 71 and the driving IC 54 of the display 5 are disposed on a transparent member 70.

[0034] 11(B) and 11(C), the signal cable 51 may have a first portion that connects the display 5 and the driving IC 54, and a second portion that connects the driving IC 54 and the control board 30. As shown in Fig. 10, the signal cable 51 may be an FPC cable. This makes it easier to connect the display 5 arranged outside the housing and the control board 30 arranged inside the housing.

[0035] The housing may have an upper case 3 and a lower case 2. In this case, the first surface is the upper surface of the upper case 3.

[0036] According to the present invention, the opening 25 is provided on the outer surface of the housing, particularly on the upper surface. The opening 25 allows the signal cable 51 to be arranged from the inside to the outside of the housing, and allows the display 5 to be attached to the outer surface of the housing. That is, the signal cable 51 is connected to the control board 30 through the opening 25. Since the display 5 is provided on the outer surface of the housing, the user is unlikely to get the impression that the display 5 is recessed. Therefore, the display 5 is easy for the user to see. The short side of the display 5 to which the signal cable 51 is connected may be the short side farther from the second surface (front surface of the display 5) of the two short sides of the display 5. In this case, the opening 25 may be provided on the rear end side of the backbone member 36 or the like. The short side of the display 5 to which the signal cable 51 is connected may be the short side closer to the second surface (front surface) of the two short sides of the display 5. In this case, the opening 25 may be provided on the front end side of the backbone member 36 or the like. The backbone member 36 of the upper case 3 is supported by the control board 30. This helps to improve the rigidity of the housing. Furthermore, by making the thickness of the backbone member 36 thicker than the thickness of other parts of the upper case 3, the structure of the upper case 3 itself is improved. In particular, by increasing the rigidity of the backbone member 36, it becomes easier to protect the display 5.

[0037] As described with reference to Figs. 8(A) to 8(E), the first surface (top surface) of the upper case 3 has an opening 25. The opening 25 functions as a hole-like or notched passage for passing the signal cable 51 from the outside to the inside of the housing. As shown in Fig. 8(B) and other figures, the opening 25 may be a slit provided along the short direction (x-axis direction) of the first surface. As shown in Fig. 8(E) and other figures, the opening 25 may be a slit provided along the long direction (z-axis direction) of the first surface. As shown in Fig. 7(C), the driving IC 54 may be accommodated inside the housing. This reduces the size of the mounting portion for the display 5. As shown in Fig. 1 and other figures, the long direction of the display 5 and the long direction of the first surface are parallel to each other.

[0038] As shown in FIG. 5 and the like, the cover member 4 is adopted as a holding member for holding the display 5 provided on the outer surface of the housing. This allows the display 5 to be arranged on the outer surface of the housing, making it easier for the user to see the information displayed on the display 5. By arranging the cover member 4 on the outside of the housing in this way, the display area of ​​the display 5 can be enlarged. However, when the display 5 is arranged on the outer surface of the housing, the display 5 is more susceptible to external impact. Therefore, the cover member 4 has a role of protecting the display 5. Furthermore, as shown in FIG. 5 and FIG. 10 and the like, the shield member 50 is an example of a shield member provided on at least a part of the side surface of the display 5. As shown in FIG. 13 and the like, the cover member 4 is an example of a cover member that sandwiches the shield member 50 between the side surface of the display 5 and the cover member 4, and covers at least a part of the side surface of the display 5. In this way, the shield member 50 also has a role of protecting the display 5 from impact.

[0039] 5, the cover member 4 may have a window portion 40 that exposes the display area of ​​the display 5. The cover member 4 may be configured to cover a non-display area of ​​the display 5. The non-display area is a portion of the upper surface of the display 5 that does not display information.

[0040] Of the four frames around the window 40 in the cover member 4, the thickness of one frame (e.g., right frame 41b, left frame 41a) located at the end of the window 40 in the longitudinal direction is thicker than the thickness of two frames (e.g., front frame 41d, rear frame 41c) located at both ends of the window 40 in the lateral direction. This makes it easier to ensure the display area of ​​the display 5 in the lateral direction. The cover member 4 may be configured to engage with a protruding portion protruding from the first surface. For example, a protruding portion (fringe 47) protruding from the top surface of the upper case 3 may engage with a notch 46 of the cover member 4.

[0041] The shielding member 50 may be electrically connected to the ground line of the signal cable 51. In this way, the shielding member 50 reduces the effect of electrical noise on the display 5.

[0042] 13, the length of the short side of the first surface of the upper case 3 is approximately equal to the sum of the length of the short side of the display 5, the thickness of the side surfaces (central leg 43) located at both ends of the short side direction of the cover member 4, and the thickness of the shield member 50 (right wall 50b, left wall 50c). This makes it possible to make the length of the short side of the display 5 closer to the length of the short side of the top surface of the photoelectric switch 1, while protecting the display 5 with the shield member 50. In other words, it becomes easier to increase the size of characters that can be displayed on the display 5.

[0043] 10, the signal cable 51 and the shielding member 50 may be integrated into an FPC cable. This makes it possible to reduce the number of parts. Also, it becomes easier to integrate the ground line to the shielding member 50 with the signal cable 51.

[0044] 10, 11(B), etc., the FPC cable may be bent at least at one location. Furthermore, a part of the shielding member 50 and a part of the signal cable 51 may overlap each other.

[0045] The shield member 50 may have a first region (bottom 50a) covering the bottom surface of the display 5, a second region (right wall 50b) protecting the first side surface of the display 5, a third region (left wall 50c) protecting the second side surface of the display 5, and a fourth region (front wall 50d) protecting the third side surface of the display 5. As shown in Fig. 10, the second region, the third region, and the fourth region may be connected to the first region.

[0046] The upper cover 19 is an example of an openable / closable lid that covers the reception unit and the display 5 covered by the cover member 4. This makes it difficult for oil droplets generated in the factory to adhere to the adjustment buttons 9 and the display 5. It also makes it difficult for the adjustment buttons 9 and the display 5 to be damaged. The cover member 4 is a cover that covers part of the display 5, and is provided on the outside of the first surface of the housing. As shown in Fig. 6(B) and Fig. 9(B), the height of the top surface of the cover member 4 in the height direction of the housing may be approximately the same as the height of the surface of the first surface on which the reception unit is provided.

[0047] 1 and the like, the opening 25 may be covered by a cover member 4 or a display 5. This makes it difficult for foreign matter to enter the inside of the housing through the opening 25.

[0048] Characters may be written on the surface of one of the frames (e.g., rear frame 41c) located at the end of the longitudinal direction of the window portion 40. For example, when a transmission type fiber is used, there are operation modes such as D-ON (dark-on) in which the indicator light 24 turns on when a workpiece is detected, and L-ON (light-on) in which the indicator light 24 turns off when a workpiece is detected. In this case, the display 5 may display a mark (e.g., an arrow mark) that indicates either "L-ON" or "D-ON" printed on the rear frame 41c. Since the rear end of the display 5 and the rear frame 41c are adjacent to each other, the display 5 may display information linked to the information displayed on the rear frame 41c.

[0049] 7(A), the display 5 may have a transparent member (transparent member 70), an OLED (OLED layer 71) provided on the lower surface side of the transparent member, and a substrate (transparent substrate 72, backbone member 36) provided on the lower surface side of the OLED. The cover member 4 is provided so as to protect at least the OLED layer 71. This reduces damage to the OLED layer 71 and the effects of electrical noise.

[0050] 13, the thickness of the cover member 4 is thinner than the thickness of the housing (upper case 3 and lower case 2). This makes it possible to make the length of the short side of the display 5 as long as possible. It also makes it possible to increase the display area of ​​the display 5, and therefore the size of the characters displayed.

[0051] In the above embodiment, the photoelectric switch 1 is used as an example of the sensor unit. However, the sensor unit may be a sensor unit that detects other physical quantities, such as a pressure sensor. The light receiving element 33 is an example of a detection unit, but may be a detection element that detects a physical quantity (e.g., amount of received light or pressure) detected from a detection target and outputs a detection signal according to the physical quantity. The display 5 is an example of a display unit that displays the physical quantity detected by the detection unit. The indicator light 24 and an output cable to the outside are examples of an output unit that outputs a comparison result between the physical quantity detected by the detection unit and a threshold value. The adjustment button 9 is an example of a reception unit or operation unit that receives an adjustment operation of the threshold value. In addition, the adjustment button 9 is an example of a threshold adjustment unit that adjusts the threshold value. The controller 6 is an example of a display control unit that displays the threshold value adjusted through the reception unit and a signal value indicating the physical quantity detected by the detection unit in the display area of ​​the display unit. The connection unit of the display 5 is disposed between the adjustment button 9 and the display area (OLED layer) of the display 5.

[0052] As shown in FIG. 3, the lower case 2 is a lower case with an open surface and a concave cross section. The upper case 3 is configured to cover the upper surface of the lower case 2. The upper case 3 and the lower case 2 form a housing for the photoelectric switch 1. The control board 30 is an example of a first board, and is housed in the lower case 2 so as to face a third surface located adjacent to the first surface and the second surface. Here, the first surface is the upper surface of the upper case 3. The third surface is, for example, the connecting portions 17a and 17b. More strictly speaking, the third surface is one of the inner surfaces forming the lower case 2.

Claims

1. A detection unit for detecting a physical quantity from a detection target; a dot matrix display for displaying a physical quantity of the detection target detected by the detection unit; an adjustment button for adjusting a threshold value for the physical quantity; a controller that displays the threshold value adjusted via the adjustment button and the physical quantity of the detection target detected by the detection unit in a display area of ​​the dot matrix display; an indicator light that outputs a comparison result between the physical quantity detected by the detection unit and a threshold value; A first substrate on which the LED of the indicator light is mounted; four frames surrounding a window portion that exposes a display area of ​​the dot matrix display; the indicator lamp, the dot matrix display, and the adjustment button are arranged in the following order along a longitudinal direction of the dot matrix display: the indicator lamp, the dot matrix display, and the adjustment button; a display area of ​​the dot matrix display is offset toward the indicator lamp along a longitudinal direction; The dot matrix display is provided with a terminal for a signal line for display on the longitudinal side of the adjustment button, The four frames cover non-display areas of the dot matrix display, A sensor unit characterized in that, of the four frames, the frame on the adjustment button side has a larger area than the frame on the indicator light side.

2. The sensor unit according to claim 1 , wherein of the four frames, the frame on the adjustment button side and the frame on the indicator light side are thicker than the other two frames.

3. The sensor unit according to claim 1 , wherein the first substrate further includes a switch mounted thereon, the switch corresponding to the adjustment button.

4. the sensor unit further includes a set button for starting automatic setting of the threshold value; 4. The sensor unit according to claim 1, wherein the set button is arranged between the dot matrix display and the indicator light along a longitudinal direction of the dot matrix display.

5. The sensor unit further includes a clamp module that clamps and holds the inserted light emitting fiber and light receiving fiber, The sensor unit according to claim 4 , wherein the clamp modules are arranged in the following order along a longitudinal direction of the dot matrix display: the clamp module, the indicator light, the set button, the dot matrix display, and the adjustment button.

6. a light receiving element for detecting an amount of light received from a detection target; a dot matrix display for displaying the amount of light received by the light receiving element; an adjustment button for adjusting the threshold value for the amount of received light; a controller for displaying the threshold value adjusted via the adjustment button and the amount of light received by the light receiving element on a display area of ​​the dot matrix display; an indicator light for outputting a result of comparing the amount of received light detected by the light receiving element with a threshold value; A first substrate on which the LED of the indicator light is mounted; four frames surrounding a window portion that exposes a display area of ​​the dot matrix display; the indicator lamp, the dot matrix display, and the adjustment button are arranged in the following order along a longitudinal direction of the dot matrix display: the indicator lamp, the dot matrix display, and the adjustment button; a display area of ​​the dot matrix display is offset toward the indicator lamp along a longitudinal direction; The dot matrix display is provided with a terminal for a signal line for display on the longitudinal side of the adjustment button, The four frames cover non-display areas of the dot matrix display, A photoelectric switch, characterized in that, of the four frames, the frame on the adjustment button side has a larger area than the frame on the indicator light side.

7. The photoelectric switch further includes a set button for starting automatic setting of the threshold value, 7. The photoelectric switch according to claim 6, wherein the set button is arranged between the dot matrix display and the indicator light along a longitudinal direction of the dot matrix display.

8. The photoelectric switch further includes a clamp module for clamping and holding the inserted light emitting fiber and the inserted light receiving fiber, The photoelectric switch according to claim 7 , wherein the clamp module is arranged along a longitudinal direction of the dot matrix display in the following order: the clamp module, the indicator light, the set button, the dot matrix display, and the adjustment button.

9. A photoelectric switch as described in claim 6, wherein, of the four frames, the frame on the adjustment button side and the frame on the indicator light side are thicker than the other two frames.

Images