JP2010261854A - Pointer-type instrument - Google Patents

Abstract

Even if a pointer-type instrument uses a stepper motor as a driving source for a pointer, the pointer is returned to the origin with a good appearance.
A part of the illumination light of the pointer 9 is emitted to the outside of the pointer 9 as pointer position detection light from an emission window 9h formed at the tip of the pointer portion 9b of the pointer 9. Of the decorative slits 7c corresponding to the scales 7 formed on the ring portion 5b of the dial plate 5, the light receiving surface of the light receiving element 13 is disposed opposite to the slits 7c of the scale portion 7a at the vehicle speed of zero. When the pointer 9 is located at the zero indicating position where the indicating portion 9b indicates the scale position 7a of the scale 7 where the vehicle speed is zero, the pointer position detection light from the exit window 9h of the pointer 9 passes through the slit 7c of the scale position 7a where the vehicle speed is zero. The light receiving element 13 receives the light. Based on the output signal of the light receiving element 13 that has received the pointer position detection light, it is recognized that the actual pointer 9 is at the zero indication position.
[Selection] Figure 5

Description

  The present invention relates to a pointer-type instrument that indicates a position corresponding to a measurement amount with a pointer.

  For example, a stepper motor is increasingly used as a driving source for a pointer in a vehicle instrument. The stepper motor has an advantage that the rotation amount of the pointer and the indicated position after the rotation can be easily defined by the number of input driving pulses. On the other hand, since the control of the stepper motor is open loop control, the control rotation amount (rotation position) may differ from the actual rotation amount (rotation position) due to step-out.

  Therefore, when the pointer is driven by a stepper motor, it is necessary to perform a return-to-origin process of the pointer as necessary. For the return-to-origin processing of the pointer, for example, a stopper piece that comes into contact with the stopper when the pointer indicates a measured value of zero is used. This stopper piece can be provided, for example, on a gear having the same rotation amount as the pointer in a gear train that transmits power between the stepper motor and the pointer. In such return-to-origin processing of the pointer using the stopper piece, a driving pulse is input to the stepper motor, the pointer is rotated from the position for indicating an appropriate measurement value to the position for indicating zero, and the stopper piece is moved. Contact the stopper. As a result, the pointer can be stopped at the zero indicated position, and the position of the control pointer can be reset to the zero indicated position.

  It has been conventionally known that the above-described origin return processing of the pointer using the stepper motor as a driving source has a problem that the pointer performs a fine reciprocating operation when the stopper piece is brought into contact with the stopper. This is because the pointer moved toward the zero indication position reversely moves in conjunction with the stopper bounced back at the moment of contact with the stopper, and the pointer reverses again with the next drive pulse of the stepper motor, indicating zero indication. This is because the movement toward the position is repeated.

  In view of this, various proposals have been made to prevent fine vibrations caused by rebounding of the pointer when the stopper piece comes into contact with the stopper by processing the waveform of the drive pulse of the stepper motor when performing the origin return processing of the pointer. (For example, Patent Document 1).

JP 2006-230030 A

  However, processing the stepper motor drive pulse when performing the return-to-origin processing of the pointer requires a detailed design to determine its contents, including what type of drive pulse is processed. is there. Therefore, various processing patterns of the stepper motor drive pulse must be designed according to the type of the pointer type instrument.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a pointer-type instrument that can return the origin in a good-looking manner even if it is a pointer-type instrument that uses a stepper motor as a drive source for the pointer. It is to provide.

  In order to achieve the above object, the pointer-type meter according to the present invention is a pointer that indicates a point corresponding to a measured amount of a scale on a dial by a pointer indicating unit disposed in front of the dial. A measuring instrument that is formed on the indicator, and that is formed at a scale corresponding to a predetermined measurement amount of the scale, Light-transmitting detection light incident that is opposed to the detection light emitting part and is surrounded by a non-light-transmitting part in a state where the pointer is at a predetermined instruction position that indicates a scale position corresponding to a measurement amount by the instruction part And a sensor that outputs a detection signal when the indication position detection light incident from the front to the rear of the dial through the detection light incident window is detected.

  According to the pointer-type meter of the present invention as set forth in claim 1, when the pointer arranged in front of the dial is at a predetermined indication position, the dial is formed at a scale corresponding to a predetermined measurement amount in the scale of the dial. The detection light emitting portion of the pointer indicating portion faces the light-transmitting detection light incident window. Then, the pointing position detection light emitted from the detection light emitting part is incident from the front to the rear of the dial through the detection light incident window. When the position of the pointer is deviated from the predetermined indication position and the detection light emitting part does not face the detection light incident window, the indication position detection light is detected because the periphery of the detection light incident window is surrounded by the opaque part. The light is not incident from the front to the rear of the dial through the light incident window. Therefore, the sensor detects the designated position detection light and outputs a detection signal only when the pointer is at the predetermined designated position.

  Therefore, by moving the pointer so as to pass through the predetermined designated position, the detection signal can be output from the sensor when the pointer is actually at the predetermined designated position. Accordingly, the pointer can be stopped at the predetermined instruction position based on the detection signal of the sensor without causing the stopper piece to contact the stopper at the predetermined instruction position of the pointer. Therefore, even if it is a pointer type instrument using a stepper motor as a driving source of the pointer, the pointer can be returned to the origin with a good appearance.

  The pointer-type meter according to the present invention described in claim 2 is the pointer-type meter according to the present invention described in claim 1, wherein the pointer transmits illumination light guided through the pointer in front of the pointer. The detection light emitting part has a light-transmitting exit window surrounded by an opaque part, and the indicated position detection light is included in the illumination light. A part of the illumination light is emitted from the exit window to the outside of the pointer.

  According to the pointer-type meter of the present invention described in claim 2, in the pointer-type meter of the present invention described in claim 1, when the pointer is a light-emitting pointer, a part of the illumination light for causing the pointer to emit light The indicated position detection light can be generated by using. Thereby, it is possible to eliminate the need for a dedicated light source for the designated position detection light.

  Furthermore, the pointer type instrument of the present invention described in claim 3 is the pointer type instrument of the present invention described in claim 2, further comprising light amount control means for controlling the light amount of the illumination light. An origin return operation mode in which the means moves the pointer and stops at the predetermined designated position based on the detection signal of the sensor, rather than the normal operation mode in which the instruction unit instructs the location corresponding to the measurement amount of the scale. And controlling to increase the amount of the illumination light.

  According to the pointer-type instrument of the present invention described in claim 3, in the pointer-type instrument of the present invention described in claim 2, the predetermined indication of the pointer using the detection signal output from the sensor that has detected the indicated position detection light. The illumination light has a higher light intensity in the origin return operation mode in which the stop control is performed than in the normal operation mode in which the stop control at the position is not performed. For this reason, the light amount of the indicated position detection light that uses a part of the illumination light is set higher in the origin return operation mode that requires detection by the sensor than in the normal operation mode that does not require detection by the sensor. Light detection accuracy can be increased.

  Further, the pointer-type meter according to the present invention described in claim 4 is the pointer-type meter according to the present invention described in claim 2 or 3, wherein the pointer-type meter is disposed in front of the pointer, and the scale and the indicator are turned off when the illumination light is turned off. It further comprises a front cover that makes the pointer invisible and enables the scale and the pointer to be visually recognized when the illumination light is turned on.

  According to the pointer type instrument of the present invention described in claim 4, in the pointer type instrument of the present invention described in claim 2 or 3, the front cover is transmitted through the front cover by the front cover disposed in front of the pointer. The amount of light incident from the front to the rear is suppressed. For this reason, natural light or the like outside the pointer-type instrument that has passed through the front cover and entered the back thereof is prevented from entering the back from the front of the dial through the detection light entrance window with a high amount of light. As a result, it is possible to prevent natural light or the like outside the pointer-type meter from being erroneously detected as the pointing position detection light by the sensor, and to perform the origin return operation of the pointer with high accuracy.

  Furthermore, the pointer-type meter according to the present invention described in claim 5 is the pointer-type meter according to the present invention described in claim 1, 2, 3 or 4, wherein the scale location corresponding to each measurement amount of the scale is Light transmissive windows each surrounded by an opaque portion are formed, and the detection light incident window is configured by the light transmissive window at a scale corresponding to the predetermined measurement amount. Of the optical paths of the indicated position detection light that are incident from the front to the back of the dial through the light transmission windows, the detection light is incident from the front to the rear of the dial through the detection light incident window. It is arranged only on the optical path of the incident indicated position detection light.

  According to the pointer-type meter of the present invention as set forth in claim 5, in the pointer-type meter of the present invention as set forth in claim 1, 2, 3 or 4, the detection light formed at the scale corresponding to the predetermined measurement amount The entrance window is indistinguishable from the light transmission window formed at each of the scale locations corresponding to other measurement quantities. Therefore, it is possible to form the detection light incident window necessary for detecting the predetermined designated position of the pointer at the scale corresponding to the predetermined measurement amount so that there is no visual discomfort.

  According to the pointer-type instrument of the present invention, even if it is a pointer-type instrument that uses a stepper motor as a drive source for the pointer, the pointer can be returned to the origin with a good appearance.

It is a front view of a pointer type meter concerning one embodiment of the present invention. It is a perspective view of the pointer drive unit of the pointer type meter shown in FIG. It is a principal part enlarged front view of the pointer type meter shown in FIG. It is sectional drawing of the principal part of the pointer type meter shown in FIG. It is an expanded sectional view of the scale location corresponding to the measurement amount of zero of the pointer type instrument shown in FIG. It is a block diagram which shows the electrical structure of the pointer type meter shown in FIG. It is a flowchart which shows the origin return process which the microcomputer of FIG. 6 performs according to the program stored in internal ROM. It is a principal part enlarged front view of the pointer type meter shown in FIG. It is sectional drawing of the principal part of the pointer type meter which concerns on other embodiment of this invention.

  Hereinafter, embodiments of a pointer-type meter according to the present invention will be described with reference to the drawings.

  FIG. 1 is a front view of a pointer-type instrument according to an embodiment of the present invention, FIG. 2 is a perspective view of a pointer drive unit of the pointer-type instrument shown in FIG. 1, and FIG. 3 is an enlarged view of the main part of the pointer-type instrument shown in FIG. 4 is a cross-sectional view of the main part of the pointer-type meter shown in FIG. 3, and FIG. 5 is an enlarged cross-sectional view of a scale corresponding to the zero measurement amount of the pointer-type meter shown in FIG.

  A pointer-type meter of this embodiment indicated by reference numeral 1 in FIG. 1 is mounted on a vehicle (not shown) and displays the vehicle speed of the vehicle. The pointer-type meter 1 includes a dial 5 whose periphery is covered with a turn-back plate 3, a light-emitting pointer 9 that is disposed in front of the dial 5 and indicates a scale 7 that indicates the vehicle speed of the dial 5, and a scale. 7 is a light receiving element 13 for detecting the pointer 9 at a scale location 7a (corresponding to a scale corresponding to a predetermined measurement amount in the claims) at zero vehicle speed (see FIG. 5, corresponding to the sensor in the claims). And have.

  As shown in FIG. 2, a pointer driving unit 11 that rotates the pointer 9 is disposed behind the dial 5. The pointer drive unit 11 includes a stepper motor 11a that rotates the pointer 9, and a wiring board 11b on which the stepper motor 11a is attached to the back surface. The output shaft 11c of the stepper motor 11a projects through the wiring board 11b and protrudes to the surface side. A light emitting diode (LED) 11d that outputs illumination light for causing the pointer 9 to emit light is mounted on the surface of the wiring board 11b. The amount of illumination light emitted by the LED 11d can be switched between a normal light amount (luminance) and a maximum light amount (maximum luminance).

  The pointer 9 includes a base portion 9a and an instruction portion 9b that is connected to the base portion 9a and points to the scale 7. The entirety of the pointer 9 having the base portion 9a and the instruction portion 9b is configured by covering a pointer main body 9c made of a translucent member with a pointer cover 9d made of a light shielding member.

  A pointer rod 9e that is press-fitted into the output shaft 11c of the stepper motor 11a is formed at the base portion 9a of the pointer cover 9d. In addition, a light receiving portion 9f for causing the illumination light of the LED 11d to enter the inside of the pointer main body 9c is formed in the base 9a portion of the pointer main body 9c. In FIG. 2, the light receiving portion 9 f is illustrated in a simplified (compact) shape for easy viewing of the drawing. However, the actual light receiving portion 9f is formed so that the illumination light of the LED 11d can be incident on the inside of the pointer main body 9c regardless of the location on the scale 7 where the indication portion 9b of the pointer 9 indicates. .

  Further, the indicator 9b portion of the pointer cover 9d includes a slit 9g for emitting the illumination light guided through the pointer body 9c to the front of the pointer 9, and the illumination light from the tip of the indicator 9b. An exit window 9h (corresponding to the detection light exit portion in the claims) for exiting on the extension line is formed.

  As shown in FIGS. 1 and 3, the dial plate 5 has an inner base portion 5a and a ring portion 5b extending in an arc shape on the outer periphery thereof. As shown in FIG. 4, the ring portion 5b bulges in a trapezoidal cross section in front of the pointer-type meter 1 with respect to the base portion 5a, and this bulged portion creates a space between the ring substrate 5b and the wiring board 11b. It is defined.

  As shown in FIG. 3, each scale 7 of the dial 5 shown in FIG. 1 includes a scale member 7b for decoration arranged on the base portion 5a of the dial 5 and a slit for decoration formed on the ring portion 5b. 7c (corresponding to the light transmission window in the claims). As shown in FIG. 4, the scale member 7b is fitted into the base portion 5a and partially protrudes from the surface 5c of the base portion 5a. The slit 7c is formed so as to penetrate the ring portion 5b from the inclined surface near the base portion 5a of the ring portion 5b to the upper surface.

  As shown in FIG. 3, when the pointer-type meter 1 is viewed from the front, if the indicator 9b of the pointer 9 indicates any scale 7, the scale member 7b is visually recognized by overlapping the front end of the indicator 9b. . The slit 7c is positioned on the extension line of the indicating portion 9b of the pointer 9 and faces the emission window 9h of the indicating portion 9b.

  As shown in FIG. 4, a front cover 15 is disposed in front of the dial plate 3, the dial plate 5 (including the scale 7), and the pointer 9. The front cover 15 is attached to the front opening of the case (not shown) of the pointer-type meter 1. The front cover 15 is composed of, for example, a smoke translucent resin material having a light transmittance of 20% to 50%, a colored glass, or a member in which a translucent colored film is attached to a transparent glass base material. When the LED 11d is lit and illumination light is emitted from the slit 9g with a normal light amount or a maximum light amount and the pointer 9 emits light, the front cover 15 is visible from the front of the front cover 15 with the scale 7 and the pointer 9 visible. Is possible. On the other hand, when the LED 11d is turned off and illumination light is not emitted from the slit 9g and the pointer 9 is not emitting light, the scale 7 and the pointer 9 from the front of the front cover 15 cannot be viewed. Note that external light such as natural light that enters the back cover 15 through the front cover 15 from the outside of the pointer-type meter 1 is much larger than the normal light emission amount of the pointer 9 due to the transmission of the front cover 15. Is attenuated to a low light intensity (luminance).

  As shown in FIG. 5, the light receiving element 13 is provided only in the scale portion 7a where the vehicle speed is zero, and is disposed in a space between the ring portion 5b and the wiring board 11b. The light receiving surface of the light receiving element 13 is opposed to a slit 7c (corresponding to a detection light incident window in claims) formed in a graduation portion 7a having a vehicle speed of zero. A polarizing filter 13a is disposed between the light receiving surface of the light receiving element 13 and the slit 7c of the graduation portion 7a facing the light receiving surface. The polarizing filter 13a allows the slit 5c of the scale portion 7a to pass through the slit 5c of the scale portion 7a from the front surface 5c side of the base portion 5a of the dial plate 5 (corresponding to the front of the dial plate in the claims). The light incident on the back of the light is linearly polarized light.

  When the pointer 9 is positioned at the zero indicating position where the indicating portion 9b indicates the scale location 7a where the vehicle speed is zero, the emission window 9h at the tip of the indicating portion 9b faces the slit 7c of the scale location 7a. Accordingly, a part of the illumination light (indicated position detection light) emitted from the emission window 9 h passes through the slit 7 c and the polarization filter 13 a to become linearly polarized light and reaches the light receiving surface of the light receiving element 13. When the pointing position detection light from the pointer 9 that has become linearly polarized light reaches the light receiving surface of the light receiving element 13, the light receiving element 13 outputs a detection signal.

  The level of the detection signal changes according to the amount of light received by the light receiving element 13 (light receiving luminance). When the illumination light of the pointer 9 is a normal light amount, the level of the output signal of the light receiving element 13 becomes a normal level. When the illumination light of the pointer 9 has the maximum light amount, the level of the output signal of the light receiving element 13 becomes the maximum level. When external light that has entered the interior through the front cover 15 passes through the slit 7c and the polarization filter 13a and becomes linearly polarized light and reaches the light receiving surface of the light receiving element 13, it is below the normal amount of illumination light. Since it is the light amount, the level of the output signal of the light receiving element 13 is further lower than the normal level.

  Next, with reference to the block diagram of FIG. 6, the electrical configuration of the pointer-type meter 1 of the present embodiment will be described. The stepper motor 11 a and the LED 11 d shown in FIG. 2 and the light receiving element 13 shown in FIG. 5 are connected to a microcomputer (hereinafter abbreviated as “microcomputer”) 21.

  The microcomputer 21 includes a ROM that stores a control program and the like, and a RAM that is used as a work area and the like. The microcomputer 21 is supplied with stabilized power from a power source 23 connected to a battery B of a vehicle (not shown) regardless of whether the ignition switch IGN of the vehicle is on or off. Further, an interface (I / F) 25 is connected to the microcomputer 21 in order to detect the on / off state of the ignition switch IGN. The microcomputer 21 that has detected the on / off state of the ignition switch IGN using the interface 25 supplies power for operation to the stepper motor 11a, the LED 11d, and the light receiving element 13 only when the ignition switch IGN is on.

  The microcomputer 21 having such a configuration performs normal operation mode processing performed in accordance with a control program stored in a built-in ROM. In the process of the normal operation mode, the vehicle speed of a vehicle (not shown) on which the pointer-type meter 1 is mounted is calculated based on a vehicle speed pulse input from a vehicle speed sensor (not shown). Then, a driving pulse is output to the stepper motor 11a, and the pointer 9 is rotated so that the instruction unit 9b indicates a position corresponding to the calculated vehicle speed (measured amount) in the scale 7.

  In the normal operation mode, the microcomputer 21 causes the LED 11d to emit light with a normal light amount (luminance). Therefore, when the pointer 9 is at the zero indication position, the indication position detection light with a normal light amount reaches the light receiving surface of the light receiving element 13 and the light receiving element 13 outputs an output signal of a normal level. The level of this output signal is compared with a predetermined threshold value in the microcomputer 21.

  The predetermined threshold is set to a value higher than the normal level and lower than the maximum level. Therefore, in the normal operation mode, the level (normal level) of the output signal of the light receiving element 13 does not reach the predetermined threshold value even when the pointer 9 is at the zero indication position. Therefore, the microcomputer 21 does not detect the pointer 9 at the zero indication position.

  Next, the outline of the processing in the origin return operation mode of the pointer 9 in the control performed according to the control program stored in the ROM built in the microcomputer 21 will be described with reference to the flowchart of FIG. The processing in the home return operation mode of FIG. 7 is as follows when the occurrence of a situation requiring the home return processing (satisfaction of conditions) defined by the control program stored in the ROM is confirmed by the microcomputer 21. To be executed. In addition, the process of step S101-step S105 demonstrated below is performed as a normal origin return process. When the pointer 9 cannot be returned to the actual zero indication position by the normal origin return process, the processes after step S107 are executed as the origin return process at the time of abnormality corresponding to the pointer origin return method according to the present invention. Is done.

  First, the microcomputer 21 switches the light amount of the illumination light from the LED 11d from the normal light amount to the maximum light amount. Thereby, the pointer 9 is caused to emit light (light up) with the maximum amount of illumination light (step S101). Next, it is confirmed whether or not an output signal having a level exceeding a predetermined threshold is input from the light receiving element 13 (step S103). When an output signal having a level exceeding a predetermined threshold is input from the light receiving element 13 (YES in step S103), it is assumed that the pointer 9 is already at the zero indication position indicated by the solid line in FIG. This is performed (step S119). In this normal termination process, the output of the drive pulse to the stepper motor 11a is terminated and the movement of the pointer 9 is stopped. Then, it is assumed that the current position of the pointer 9 for control is the zero indication position of the pointer 9 for control. If the normal termination process is performed, the amount of illumination light from the LED 11d is switched from the maximum amount to the normal amount (step S121). Thereafter, the origin return process is terminated.

  If an output signal having a level exceeding a predetermined threshold value is not input from the light receiving element 13 (NO in step S103), the pointer 9 is brought close to the actual zero indication position and the predetermined threshold is set from the light receiving element 13. In order to confirm the input of the output signal at a level higher than the value, a process of moving the pointer 9 toward the zero indication position on control at a predetermined speed (returning to zero) by outputting a drive pulse to the stepper motor 11a. Execute (Step S105). Then, during the movement of the pointer 9, it is confirmed whether or not the reverse rotation angle of the control pointer 9 is greater than or equal to the maximum deflection angle (step S107). Whether or not the reverse rotation angle of the pointer 9 for control is greater than or equal to the maximum deflection angle can be confirmed by whether or not the movement time of the pointer 9 has reached the upper limit time. This upper limit time is the time required for the entire range of the range in which the pointer 9 can rotate at a predetermined speed.

  If the reverse angle of the pointer 9 is not equal to or greater than the maximum deflection angle (NO in step S107), the process returns to step S103. If the angle is equal to or greater than the maximum deflection angle (YES in step S107), the microcomputer 21 determines that the position of the control pointer 9 has reached the start point of the movement range indicated by the imaginary line in FIG. The microcomputer 21 changes the driving pulse output to the stepper motor 11a to rotate the pointer 9 forward by 10 ° (step S109). Here, the forward rotation of the pointer 9 by 10 ° is a movement amount that exceeds the forward rotation movement amount of the pointer 9 from the start point of the movement range to the zero indication position. By the forward rotation of the pointer 9 for 10 °, the microcomputer 21 moves the position of the pointer 9 on the control from the starting point of the moving range to the reference point ahead of the zero indication position.

  Next, the microcomputer 21 again brings the pointer 9 close to the actual zero indication position, and in order to confirm the input of the output signal from the light receiving element 13 at a level equal to or higher than a predetermined threshold value, the driving pulse output to the stepper motor 11a. Is changed, the process of moving (returning to zero) the pointer 9 toward the zero instruction position on the control at a predetermined speed is executed again (step S111). Then, it is confirmed whether or not an output signal having a level exceeding a predetermined threshold value is input from the light receiving element 13 while the pointer 9 is moving (step S113).

  When an output signal having a level exceeding a predetermined threshold is input from the light receiving element 13 (YES in step S113), it is assumed that the pointer 9 is already at the zero indication position, and the normal termination process in step S119 and step S121 are performed. The illumination light is switched from the maximum light amount to the normal light amount. When an output signal having a level exceeding a predetermined threshold value is not input from the light receiving element 13 (NO in step S113), it is confirmed whether or not the reverse angle of the control pointer 9 is 10 ° or more. (Step S115). Whether or not the reverse angle of the pointer 9 for control is equal to or greater than 10 ° can be confirmed by whether or not the movement time of the pointer 9 has reached the reference time. This reference time is the time required for the pointer 9 to rotate 10 ° at a predetermined speed.

  If the reverse angle of the pointer 9 is not 10 ° or more (NO in step S115), the process returns to step S113. If it is 10 ° or more (YES in step S115), the microcomputer 21 performs an abnormal end notification process assuming that the actual pointer 9 cannot reach the zero indication position (step S117). In this abnormal end notification process, the output of the drive pulse to the stepper motor 11a is ended and the movement of the pointer 9 is stopped. Then, an abnormality notification operation is executed. In the abnormality notification operation, for example, a diagnosis signal indicating a position abnormality of the pointer 9 is output to an ECU (not shown) of the vehicle to which the microcomputer 21 is connected. Of course, other operations may be performed. If the abnormal end notification process is performed, the amount of illumination light from the LED 11d is switched from the maximum amount to the normal amount (step S121). Thereafter, the origin return process is terminated.

  As is clear from the above description, in the present embodiment, the microcomputer 21 that performs the processes of step S101 and step S121 constitutes the light amount control means in the claims.

  As described above, according to the pointer-type meter 1 of the present embodiment, when the actual pointer 9 has not reached the zero indication position in the normal origin return processing (step S101 to step S105 in FIG. 7). In addition, the home position return process at the time of abnormality (steps S107 to S117 in FIG. 7) is executed. In each return to origin process, if an output signal having a level exceeding a predetermined threshold value is input from the light receiving element 13, the actual pointer 9 is assumed to be at the zero indicating position, and the pointer 9 is stopped at that position. Thus, the zero indication position of the control pointer 9 is set to the current position of the control pointer 9.

  For this reason, even if it is difficult to mechanically stop the movement of the pointer 9 at the zero indication position by bringing the stopper piece into contact with the stopper, the pointer based on the output signal from the light receiving element 13 is used. 9 can be stopped at the zero indication position. Therefore, even if the stepper motor 11a is used as the driving source of the pointer 9, the pointer 9 can be returned to the zero indication position (origin) with good appearance without vibrating.

  The specific movement pattern of the pointer 9 in the origin return operation mode is not limited to the above-described pattern of FIG. For example, whether or not the actual pointer 9 has reached the zero indication position during the forward rotation of the position of the pointer 9 on the control by 10 ° from the start point of the moving range to the reference point ahead of the zero indication position in step S109 You may confirm whether or not. In addition, when the pointer 9 is rotated forward by 10 ° in step 109 and when the pointer 9 is moved (returned to zero) toward the zero indication position in control at a predetermined speed in steps S111 to S115 in FIG. In both cases, it may be confirmed whether or not the actual pointer 9 has reached the zero indication position.

  In this embodiment, the illumination light of the pointer 9 is set to the normal light amount in the normal operation mode, and the illumination light of the pointer 9 is set to the maximum light amount in the origin return operation mode. The amount of illumination light of the pointer 9 may be the same in the operation mode. In this case, each process of step S101 and step S121 in FIG. 7 is omitted. In this case, the process for confirming whether the actual pointer 9 has reached the zero indication position based on the output signal from the light receiving element 13 is not performed during the normal operation mode.

  Furthermore, in the present embodiment, the light receiving element 13 is disposed in the space between the ring portion 5b of the scale point 7a at the vehicle speed zero and the wiring board 11b, and the light receiving surface of the light receiving element 13 is slit at the scale point 7a at the vehicle speed zero. It was arranged to face 7c. However, as shown in FIG. 9, the light receiving element 13 is attached to the wiring board 11b so that the light receiving surface faces the space between the ring portion 5b of the scale point 7a at zero vehicle speed and the wiring board 11b, and light is received from the polarizing filter 13a. The element 13 may be configured to guide the pointing position detection light by the prism 17.

  Further, the polarizing filter 13a disposed opposite to the slit 7c of the scale portion 7a with zero vehicle speed shown in FIGS. 5 and 9 may be omitted.

  Furthermore, in the present embodiment, the exit window 9h of the pointer 9 and the slit 7c of the ring portion 5b of the dial plate 5 are configured by openings, but the exit window 9h and / or slit 7c (or one of them) is formed by a transparent member that closes the opening. May be configured.

  In the present embodiment, each scale 7 has a decorative slit 7c. However, only the scale portion 7a having a vehicle speed of zero may have a slit 7c. However, if each scale 7 is configured to have a decorative slit 7c, the presence of the slit 7c can be made less uncomfortable than a configuration in which only the scale portion 7a having a vehicle speed of zero has the slit 7c. .

  Further, in the present embodiment, the front cover 15 disposed in front of the dial plate 3, the dial plate 5, and the pointer 9 may have a light transmittance of 100% or a transparent one close thereto. In that case, light emission by the illumination light of the pointer 9 is performed only in the origin return operation mode even in the daytime when the illumination light of the pointer 9 is not emitted by an operation of a steering switch (not shown) or the like. Whether or not the actual pointer 9 is at the zero indication position can be confirmed based on the output signal of the light receiving element 13.

  On the other hand, if the front cover 15 is made of, for example, a smoke-colored translucent resin material having a light transmittance of 20% to 50% as in this embodiment, the operation of the pointer 9 in the origin return operation mode is performed by illumination light. It can be performed with light emission.

  Further, a dedicated light source may be used to emit the pointing position detection light from the pointer 9 at the zero pointing position. However, when the pointer 9 is a light emission type pointer as in the present embodiment, if the pointing position detection light is emitted from the pointer 9 using a part of the illumination light of the pointer 9, the number of components and the configuration The structure for causing the pointer 9 to emit light can be effectively used for emitting the pointing position detection light from the pointer 9.

  Further, in this embodiment, the position where the light receiving element 13 receives the pointing position detection light from the pointer 9 and detects the actual pointer 9 based on the output signal is set as the zero pointing position. The position where the actual pointer 9 is detected by receiving the designated position detection light is not limited to the zero designated position, but is arbitrary. For example, the light receiving element 13 may be arranged in a space between the ring portion 5b and the wiring board 11b as shown in FIG. 5 so as to face the slit 7c of the scale 7 of 20 km / h shown in FIG. Alternatively, the scale 7 shown in FIG. 1 is also formed at a location lower (minus) than 0 km / h, and a slit 7c (not shown) is formed at a corresponding location of the ring portion 5b, and is opposed to the slit 7c. Then, as shown in FIG. 5, the light receiving element 13 may be arranged in a space between the ring portion 5b and the wiring board 11b. In this way, if the position is known in advance, instead of the zero indication position, the position where the indication position detection light from the pointer 9 is received by the light receiving element 13 and the actual pointer 9 is detected by the output signal is minus. It can be set as the arbitrary positions including the scale 7 portion.

  Further, when a predetermined position other than the zero indication position is a position where the light receiving element 13 receives the designated position detection light from the pointer 9 and detects the actual pointer 9, the light receiving element 13 detects the pointer 9. When the pointing position detection light from the head is received, the position of the pointer 9 on the control is reset to a predetermined position. For example, the pointer 9 is then zeroed by the driving force of the stepper motor 11a under the control of the microcomputer 21. It can also be returned to position.

  Furthermore, in the present embodiment, the case where the driving source of the pointer 9 is the stepper motor 11a has been described as an example. However, the present invention can also be applied to a case where a motor other than the stepper motor is used as the driving source of the pointer 9. It is.

  In the present embodiment, the pointer type instrument 1 mounted on the vehicle has been described as an example. However, the present invention can be widely applied to a pointer-type instrument used in other than a vehicle.

  The present invention is suitable for use in a pointer-type instrument that performs return-to-origin of a pointer.

DESCRIPTION OF SYMBOLS 1 Pointer type meter 3 Dial plate 5 Dial 5a Base part 5b Ring part 5c Front surface 5d Back surface 7 Scale 7a Scale location of zero vehicle speed (scale location corresponding to predetermined measurement amount)
7b Scale member 7c Slit (light transmission window, detection light incident window)
9 Pointer 9a Base 9b Pointer 9c Pointer body 9d Pointer cover 9e Pointer rod 9f Light receiving part 9g Slit 9h Output window (detection light output part)
11 Pointer drive unit 11a Stepper motor 11b Wiring board 11c Output shaft 11d LED
13 Light receiving element (sensor)
13a Polarizing filter 15 Front cover 17 Prism 21 Microcomputer (light quantity control means)
23 Power supply 25 Interface B Battery IGN Ignition switch

Claims (5)

A pointer-type instrument that indicates a point corresponding to a measurement amount of a scale on a dial by an indicator indicating a pointer disposed in front of the dial,
A detection light emitting unit that is formed in the pointing unit and emits the pointing position detection light of the pointer;
The detection light emitting unit in a state where the pointer is located at a predetermined indication position that is formed at a graduation location corresponding to a predetermined measurement amount in the scale, and indicates the graduation location corresponding to the predetermined measurement amount by the indication portion. A light-transmitting detection light incident window whose periphery is surrounded by a light-impermeable portion;
A sensor that outputs a detection signal when detecting the indication position detection light that is incident from the front to the back of the dial through the detection light incident window;
A pointer-type instrument characterized by comprising:   The pointer is a light-emitting pointer that emits illumination light guided inside the pointer to the front of the pointer, and the detection light emitting portion is light transmissive and is surrounded by an opaque portion. 2. The light source according to claim 1, wherein the pointing position detection light includes a part of the illumination light emitted from the emission window to the outside of the pointer. The pointer-type meter according to 1.   The light amount control unit further controls the light amount of the illumination light, and the light amount control unit moves the pointer more than the normal operation mode in which the instruction unit indicates a location corresponding to the measurement amount of the scale. 3. The pointer-type instrument according to claim 2, wherein control is performed to increase the amount of illumination light in an origin return operation mode in which the sensor stops at the predetermined designated position based on the detection signal of the sensor.   A front cover that is disposed in front of the pointer and that makes it impossible to visually recognize the scale and the pointer when the illumination light is turned off, and allows the scale and the pointer to be visually recognized when the illumination light is turned on; The pointer-type meter according to claim 2 or 3, characterized in that   A light transmission window surrounded by an opaque portion is formed at each of the scale locations corresponding to each measurement amount of the scale, and the light transmission window at the scale location corresponding to the predetermined measurement amount. The detection light incident window is configured, and the sensor is configured to detect the detection light among the optical paths of the indication position detection light incident from the front to the rear of the dial through the light transmission windows. 5. The pointer-type meter according to claim 1, wherein the pointer-type meter is disposed only on an optical path of the indication position detection light incident from the front to the rear of the dial through an entrance window. .

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