JP5165459B2 - Tilt sensor - Google Patents

Description

  The present invention relates to a tilt sensor for detecting the tilt direction of a digital still camera or a mobile phone, for example.

  8 and 9 show an example of a conventional tilt sensor. The tilt sensor X shown in the figure includes a substrate 91, a case 92, a cover 93, a pair of light receiving elements 94A and 94B, a light emitting element 95, and a rolling element 96. In FIG. 9, the cover 93 is omitted for convenience of understanding. The pair of light receiving elements 94A and 94B and the light emitting element 95 are mounted on the surface of the substrate 91 and are surrounded by a case 92. A gap 92 a is formed by the case 92 and the cover 93. The gap 92a is shaped such that light from the light emitting element 95 is incident and light reflected by each part of the case 92 can reach the pair of light receiving elements 94A and 94B. A rolling element 96 is accommodated in the gap 92a. The rolling element 96 has a cylindrical shape and can roll in the gap 92a. On the back surface of the substrate 91, for example, mounting terminals used for surface mounting on a circuit board are formed.

  The state shown in FIG. 9 is a state where the rolling element 96 is in a position overlapping the light emitting element 95 according to gravity. At this time, since almost all the light emitted from the light emitting element 95 is blocked by the rolling element 96, the light does not reach any of the pair of light receiving elements 94A and 94B. Next, when the tilt sensor X is tilted to the left from the state shown in FIG. 9, the rolling element 96 takes a position overlapping the light receiving element 94A. In this state, light from the light emitting element 95 is received only by the light receiving element 94B. Conversely, when the tilt sensor X is tilted to the right from the state shown in FIG. 9, the rolling element 96 takes a position overlapping the light receiving element 94B. In this state, light from the light emitting element 95 is received only by the light receiving element 94A. If the tilt sensor X is mounted on, for example, a circuit board, it is detected by monitoring the light reception signals of the pair of light receiving elements 94A and 94B that the circuit board is tilted about an axis extending at right angles to the circuit board. be able to. By using such a tilt sensor X, for example, a user viewing a display screen of a mobile phone detects that the display screen has been oriented vertically or horizontally, and an image to be displayed on the display screen accordingly. It is possible to perform processing such as changing the orientation of.

  However, as shown in FIG. 8, in the tilt sensor X, a space for arranging the pair of light receiving elements 94A and 94B and the light emitting element 95 and a space called a gap 92a for rolling the rolling element 96 overlap. It has a structure. For this reason, the height of the tilt sensor X has to be greater than or equal to the sum of the height of at least one of the light receiving elements 94A and 94B and the light emitting element 95 and the height of the rolling element 96.

JP 2007-139634 A

  The present invention has been conceived under the above-described circumstances, and an object thereof is to provide an inclination sensor that can be thinned.

  The tilt sensor provided by the present invention includes a light emitting element and a pair of light receiving elements that are spaced apart from each other in the in-plane direction of the detection target surface, and light from the light-emitting element due to a change in the gravitational direction in the in-plane direction. From a pair of semi-light-shielding positions that allow light from the light-emitting elements to reach only one of the pair of light-receiving elements, and from the light-emitting elements. A rolling element that takes a non-light-shielding position to reach any of the pair of light receiving elements, an exit opening that accommodates the rolling element and emits light from the light emitting element, and the pair of light receiving elements An inclination sensor connected to a pair of entrances through which light enters the element, the gap being surrounded by the light emitting element and the pair of light receiving elements in the in-plane direction. Have It is characterized in that.

  According to such a configuration, the light emitting element and the pair of light receiving elements and the rolling element are arranged along the detection target surface. For this reason, the height of the tilt sensor need not be higher than the sum of the heights of either the light emitting element or the pair of light receiving elements and the rolling element. Therefore, the thickness of the tilt sensor can be reduced.

  In a preferred embodiment of the present invention, of the surfaces that define the gap, the surface that is perpendicular to the detection target surface is uneven. According to such a structure, it is possible to suppress suitably the collision sound of the said rolling element. Such an effect is advantageous in preventing annoying sound from occurring when the tilt sensor is mounted on a mobile phone.

  In a preferred embodiment of the present invention, the gap is formed in a rectangular shape, and the exit and the pair of entrances are located at one of the rectangular vertices. According to such a configuration, it can be accurately detected that the rolling element is in any one of the non-light-shielding position, the pair of semi-light-shielding positions, and the complete light-shielding position.

  In a preferred embodiment of the present invention, the rolling element has a cylindrical shape whose central axis faces a direction perpendicular to the detection target surface. According to such a configuration, the rolling element is suitable for closing the exit port and the entrance port without a gap while relatively smoothly rolling in the gap.

  In a preferred embodiment of the present invention, the exit port and the pair of entrance ports are smaller in dimension in a direction perpendicular to the detection target surface than the rolling element. According to such a structure, shielding by the said rolling element is performed reliably.

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

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

  1 to 4 show an example of a tilt sensor according to the present invention. The tilt sensor A of this embodiment includes a substrate 1, a case 2, a light emitting element 4, a pair of light receiving elements 5 </ b> A and 5 </ b> B, and a rolling element 6. As shown in FIG. 1, the inclination sensor A is used to detect an inclination in the in-plane direction of the circuit board S in a state where the surface to be detected is surface-mounted on the circuit board S, for example. In the present embodiment, the inclination sensor A has a size of about 3.3 mm × 3.3 mm and a thickness of about 0.8 mm. In FIGS. 3 and 4, the rolling elements 6 are indicated by imaginary lines for convenience of understanding.

  The substrate 1 is a rectangular insulating substrate and is made of, for example, a glass epoxy resin. In the present embodiment, the substrate 1 has a size of about 3.3 mm × 3.3 mm and a thickness of about 0.2 mm. A wiring pattern (not shown) is formed on the substrate 1. The wiring pattern is made of, for example, a Cu—Ni—Au plating layer. This wiring pattern has portions formed on the front and back surfaces of the substrate 1 and through-hole portions that conduct these portions. A light emitting element 4 and a pair of light receiving elements 5A and 5B are die-bonded to a portion of the wiring pattern formed on the surface of the substrate 1. Further, a portion of the wiring pattern formed on the back surface of the substrate 1 is used as a mounting terminal for surface mounting the tilt sensor A on the circuit substrate S.

  The light emitting element 4 is made of, for example, an infrared light emitting diode capable of emitting infrared light, and is disposed close to one side of the substrate 1. In the present embodiment, the size of the light emitting element 4 is about 0.25 mm square.

  The pair of light receiving elements 5A and 5B are, for example, phototransistors, and are configured to generate a photoelectromotive force in response to receiving infrared rays and to flow current. As shown in FIG. 2, the pair of light receiving elements 5 </ b> A and 5 </ b> B are arranged on the substrate 1 so as to be separated from each other so that each of them is close to the opposite side of the substrate 1. In the present embodiment, the light receiving elements 5A and 5B have a size of about 0.6 mm × 0.4 mm.

  The case 2 has a rectangular parallelepiped shape as a whole, and is formed of, for example, an epoxy resin. By bonding the case 2 and the substrate 1, the gap 3 and the accommodation spaces 22, 23 </ b> A, 23 </ b> B are formed. In the present embodiment, the case 2 has a size of about 3.3 mm square and a thickness of about 0.6 mm.

  As shown in FIGS. 2 and 4, the accommodation space 22 accommodates the light emitting element 4. A portion of the case 2 that forms the accommodation space 22 is formed with an inclined surface 22 b and covered with a part of the plating layer 26. The plating layer 26 is, for example, a Cu—Ni—AU plating layer, and each thickness is set to, for example, about 30 μm, 5 μm, and 0.3 μm. An emission port 22 a is provided between the accommodation space 22 and the gap 3. The emission port 22 a is a path for emitting light from the light emitting element 4 to the gap 3. In the present embodiment, the height of the emission port 22 a is limited by the convex portions 24 and 25. The convex portion 24 is a portion where a part of the case 2 is raised, and the convex portion 25 is a resin member bonded to the substrate 1. The height direction dimension of the exit port 22 a is smaller than the height of the rolling element 6. More preferably, the height of each of the convex portions 24 and 25 is larger than the height direction difference between the rolling element 6 and the gap portion 3. The lateral dimension of the emission port 22a is about 0.6 mm. The inclined surface 22b reflects part of the light from the light emitting element 4 toward the emission port 22a.

  As shown in FIGS. 2 and 3, the accommodation spaces 23A and 23B accommodate the light receiving elements 5A and 5B, respectively. The portions of the case 2 that form the accommodation spaces 23A and 23B are formed with inclined surfaces 23Ab and 23Bb, and are covered with a part of the plating layer 26. Incident ports 23Aa and 23Ba are provided between the accommodation spaces 23A and 23B and the gap 3. The entrances 23Aa and 23Ba are paths through which light enters from the gap 3 to the light receiving elements 5A and 5B. In the present embodiment, the heights of the entrances 23Aa and 23Ba are limited by the convex portions 24 and 25. The height direction dimensions of the entrances 23 </ b> Aa and 23 </ b> Ba are smaller than the height of the rolling elements 6. More preferably, the height of each of the convex portions 24 and 25 is larger than the height direction difference between the rolling element 6 and the gap portion 3. The lateral dimension of the entrances 23Aa and 23Ba is about 0.6 mm. The inclined surfaces 23Ab and 23Bb reflect the light incident from the incident ports 23Aa and 23Ba toward the light receiving elements 5A and 5B.

  The gap 3 is a part that accommodates the rolling element 6 and is a part for rolling the rolling element 6 to a predetermined position according to the posture of the inclination sensor A. In this embodiment, it is substantially rectangular. In the present embodiment, the gap 3 has a size corresponding to a rectangle with one side of 1.3 mm. The exit 22a and the entrances 23Aa and 23Ba are located at portions corresponding to the three apexes of the gap 3. The gap 3 is defined by the top surface 20 a and the inner surface 20 c of the case 2 and the ground surface 10 of the substrate 1. The entire top surface 20 a is covered with a part of the plating layer 26. The ground 10 is covered with a plating layer 11 having the same configuration as the plating layer 26. The plated layers 11 and 26 are connected to a portion of the wiring pattern formed on the substrate 1 that is electrically connected to the ground line of the circuit board S. Moreover, the some convex part 21 is formed in the inner surface 20c. Each of the plurality of convex portions 21 has a semicircular cross section extending along the inner side surface 20c. For example, the protruding amount is about 0.1 mm.

  The rolling element 6 is used to appropriately prevent light from the light emitting element 4 from reaching the pair of light receiving elements 5A and 5B by rolling in the gap 3 in accordance with the attitude of the tilt sensor A. Is. The rolling element 6 has a cylindrical shape and is made of a relatively high density metal such as stainless steel or tungsten. In the present embodiment, the rolling element 6 has a diameter of 0.7 to 0.8 mm.

  Next, detection of the tilt direction by the tilt sensor A will be described. First, FIG. 2 shows a state in which the tilt sensor A is in the initial posture. In this figure and FIGS. 5 to 7 described later, the lower part in the figure is the vertically lower part. In the case of FIG. 2, the rolling elements 6 are located in a portion of the gap 3 on the side opposite to the exit port 22 a according to gravity. This position is referred to as a non-light-shielding position 60. Since the rolling element 6 is at the non-light-shielding position 60, the light from the light emitting element 4 is emitted from the emission port 22 a to the gap portion 3. This light is repeatedly reflected in the gap 3 and then reaches both the light receiving elements 5A and 5B via the entrances 23Aa and 23Ba. Then, a light reception signal is output from both of the light receiving elements 5A and 5B. Thereby, when the light reception signal is output from both of the light receiving elements 5A and 5B, the rolling element 6 is at the non-light shielding position 60, and the inclination sensor A is in the posture shown in the figure with respect to the vertical direction. I can recognize that.

  Next, FIG. 5 shows a state in which the tilt sensor A is rotated about 90 degrees counterclockwise from the posture shown in FIG. In this state, the rolling element 6 is located in front of the entrance 23Aa according to gravity. This position is referred to as a semi-light-shielding position 61A. As a result, the entrance 23 </ b> Aa is closed by the rolling element 6. For this reason, the light from the light emitting element 4 reaches only the light receiving element 5B via the incident port 23Ba and does not reach the light receiving element 5A. Therefore, when the light reception signal is output only from the light receiving element 5B, it can be recognized that the rolling element 6 is in the semi-light-shielding position 61A and the inclination sensor A is in the posture shown in the figure with respect to the vertical direction.

  FIG. 6 shows a state in which the tilt sensor A is rotated about 90 degrees clockwise from the posture shown in FIG. In this state, the rolling element 6 is located in front of the entrance 23Ba according to gravity. This position is referred to as a semi-light-shielding position 61B. As a result, the entrance 23Ba is closed by the rolling elements 6. For this reason, the light from the light emitting element 4 reaches only the light receiving element 5A via the incident port 23Aa and does not reach the light receiving element 5B. Therefore, when the light reception signal is output only from the light receiving element 5A, it can be recognized that the rolling element 6 is in the semi-light-shielding position 61B and the inclination sensor A is in the posture shown in the figure with respect to the vertical direction.

  FIG. 7 shows a state in which the tilt sensor A is rotated about 180 degrees from the posture shown in FIG. In this state, the rolling element 6 is located in front of the exit port 22a according to gravity. This position is referred to as a complete light shielding position 62. As a result, the exit 22a is closed by the rolling elements 6. For this reason, the light from the light emitting element 4 is completely blocked by the rolling elements 6, and does not reach any of the light receiving elements 5A and 5B. Therefore, when no light reception signal is output from either of the light receiving elements 5A and 5B, the rolling element 6 is at the complete light shielding position 62, and the inclination sensor A is in the posture shown in the figure with respect to the vertical direction. Can be recognized.

  Next, the operation of the tilt sensor A will be described.

  According to this embodiment, the light emitting element 4, the pair of light receiving elements 5A and 5B, and the rolling element 6 are arranged along the detection target surface. For this reason, the height of the inclination sensor A is the sum of the light emitting element 4, the pair of light receiving elements 5 A and 5 B, and the rolling element 6, the thickness of the substrate 1, and the thickness of the case 2. Is possible. Therefore, the thickness of the inclination sensor A can be reduced. By making the gap portion 3 rectangular, it is possible to accurately detect that the rolling element 6 is in any one of the non-light shielding position 60, the semi-light shielding positions 61A and 61B, and the complete light shielding position 62.

  By providing the plurality of convex portions 21, the inner side surface 20 c has an uneven shape. When the rolling element 6 collides with the inner side surface 20c, the convex portion 21 serves as a cushion. Thereby, it is possible to suppress suitably the collision sound of the rolling element 6. FIG. Such an effect is advantageous in preventing harsh sounds when the tilt sensor A is mounted on a mobile phone.

  The rolling element 6 having a cylindrical shape is suitable for closing the exit port 22a and the entrance ports 23Aa and 23Ba without gaps while rolling in the gap 3 relatively smoothly. In particular, since the height direction dimension of the exit port 22a and the entrance ports 23Aa and 23Ba is smaller than the height of the rolling element 6, the shielding by the rolling element 6 is surely performed. Since each of the convex portions 24 and 25 is larger than the height direction dimensional difference between the gap portion 3 and the rolling element 6, even if the rolling element 6 is located on either the top surface 20 a side or the ground 10 side, the convexity The parts 24 and 25 can be reliably shielded.

  The tilt sensor according to the present invention is not limited to the above-described embodiment. The specific configuration of each part of the tilt sensor according to the present invention can be varied in design in various ways.

  The rolling elements in the present invention are preferably cylindrical as in the above-described embodiment, but are not limited to this, and may be spherical. Light emitted from the light-emitting element is not limited to infrared light, and light having various wavelengths can be used.

It is a perspective view which shows an example of the inclination sensor which concerns on this invention. It is sectional drawing which follows the II-II line | wire of FIG. It is sectional drawing which follows the III-III line of FIG. It is sectional drawing which follows the IV-IV line of FIG. It is sectional drawing which shows the state which a rolling element takes a semi-light-shielding position. It is sectional drawing which shows the state which a rolling element takes a semi-light-shielding position. It is sectional drawing which shows the state which a rolling element takes a complete light-shielding position. It is sectional drawing which shows an example of the conventional inclination sensor. It is a principal part front view which shows an example of the conventional inclination sensor.

Explanation of symbols

A Inclination sensor S Circuit board 1 Board 2 Case 3 Gap part 4 Light emitting element 5A, 5B Light receiving element 6 Rolling element 10 Ground 11 Plating layer 20a Top surface 20c Inner side face 21 Convex part 22 Accommodating space 23A, 23B Accommodating space 22a Outlet 23Aa , 23Ba Incident port 22b Inclined surface 23Ab, 23Bb Inclined surface 24, 25 Protruding portion 26 Plating layer

Claims (4)

A light emitting element and a pair of light receiving elements that are spaced apart from each other in the in-plane direction of the detection target surface;
Due to a change in the direction of gravity in the in-plane direction, the light from the light emitting element does not reach any of the pair of light receiving elements, and the light from the light emitting element is any of the pair of light receiving elements. A rolling element having a pair of semi-light-shielding positions that reach only one side and a non-light-shielding position that allows light from the light-emitting elements to reach any of the pair of light-receiving elements;
A gap portion that accommodates the rolling element and is connected to a pair of incident ports through which light enters the pair of light receiving elements and an exit port from which light from the light emitting element is emitted;
A case in which the gap is formed;
An inclination sensor comprising:
The gap is surrounded by the light emitting element and the pair of light receiving elements in the in-plane direction ,
The rolling element has a cylindrical shape,
Of the surfaces defining the gap, the surface perpendicular to the detection target surface is formed by the inner side surface of the case, and a plurality of protrusions extending in a direction perpendicular to the detection target surface. An inclination sensor characterized in that it is made uneven by forming a portion . The gap is rectangular,
The inclination sensor according to claim 1 , wherein the exit port and the pair of entrance ports are located at any one of the rectangular vertices. The inclination sensor according to claim 1 or 2 , wherein the rolling element has a cylindrical shape whose central axis faces a direction perpendicular to the detection target surface. The inclination sensor according to claim 3 , wherein the exit port and the pair of entrance ports are smaller in dimension in a direction perpendicular to the detection target surface than the rolling element.

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