Tablet feeder

Tablets are delivered from a tablet storage case (3) mounted on a case support table (4), and when the tablets are passed through a delivery passage (9), formed in the case support table (3), quantity of the passed tablets is counted by a counting means (10). A start state of mounting of the tablet storage case (4) on the case support table (3) is detected by case detection means (8, 19), and the counting sensor (10) is kept in off state until the start state of mounting of the photon-electron conversion region is detected by the case detection (8, 19) and is set to On state after the detection. This ensures prevention of erroneous operation due to the mounting and dismounting of the tablet storage case (4) on and from the case support table (3).

TECHNICAL FIELD

The present invention relates to a tablet feeder.

BACKGROUND ART

Conventionally, there is a tablet feeder composed of a case support table on which a motor is placed, and a tablet storage case which can be mounted on or dismounted from the case support table. In this kind of the table feeder, when the motor is driven, a rotor disposed inside the tablet storage case is rotated via a plurality of gears so that tablets contained in its pocket can be discharged through a delivery passage.

In this tablet feeder, the tablets discharged from the tablet storage case are counted by a counting sensor provided on the delivery passage. There are a type of the counting sensor which maintains on state regardless of the mounting of the tablet storage case on the case support table, and a type of the counting sensor which is switched to on state only when the tablet storage case is mounted.

However, the counting sensor which constantly maintains on state may suffer erroneous operation due to external perturbations such as light from a fluorescent lamp while the tablet storage case is detached from the case support table. Also, the counting sensor which is switched to on state only when the tablet storage case is mounted on the case support table may suffer errors in the delivery quantity if tablets are accidentally dropped off before the mounting on the tablet storage case is completed and so these tablets are not detectable.

DISCLOSURE OF INVENTION

Accordingly, it is a primary object of the present invention to provide a tablet feeder capable of surely preventing erroneous operation from occurring due to the mounting and dismounting of the tablet storage case on and from the case support table.

In the present invention, as a means to solve the above problem, there is provided a tablet feeder in which tablets are delivered from a tablet storage case mounted on a case support table, and when the tablets are passed through a delivery passage formed in the case support table, quantity of the passed tablets is counted by a counting means, comprising:

case detection means for outputting a detection signal from start of mounting of the tablet storage case on the case support table, so that the counting means is kept in off state until a start state of mounting of the tablet storage case is detected by the case detection means and is set to on state after detection.

With this constitution, in the state of the tablet storage case being demounted from the case support table, the counting means can be kept in off state, which makes it possible to restrain unnecessary power consumption and also ensures prevention of the erroneous operation by the counting means due to external perturbations. Further, when the tablet storage case is mounted on the case support table, the counting means is set to on state immediately after the start of mounting. Therefore, even if tablets are accidentally dropped off from the tablet storage case, it becomes possible to reliably count the tablets by the counting means when the tablets are passed through the delivery passage, thereby preventing errors in the delivery quantity from occurring.

The tablet storage case may be provided with an information display section for displaying information about tablets to be stored, and the case support table may be provided with identification means for detecting the information display section, so that the identification means is kept in off state until a start state of mounting of the tablet storage case is detected by the case detection means and is set to on state after detection.

With this constitution, a placement position of the identification means can be determined with disregard to potential adverse influences of external perturbations.

The counting means should preferably be set to on state based on the detection signal from the case detection means after passing of noise influence time, which allows further prevention of detection errors by the counting means. Further, the case detection means may be capable of separately detecting a state from a start of mounting of the tablet storage case on the case support table to a middle of the mounting and a state from the middle of the mounting to an end of the mounting.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the invention will now be described with reference to the accompanying drawings.

FIG. 1shows a tablet feeder1according to the present embodiment. The tablet feeder1is mounted on both sides or one side of a plurality of drawer articles100which can be pulled out and are installed on a drawer case-type tablet feeding apparatus2A shown inFIG. 5, or mounted on the outer side of inner and outer double drums101,102which are rotatably supported on upper and lower end sections and installed on a drum-type tablet feeding apparatus2B shown inFIG. 6.

The tablet feeder1is composed of case support tables3, which are placed on the drawer articles100of the tablet feeding apparatus2A or a drum102of the tablet feeding apparatus2B, and tablet storage cases4which can be mounted on or dismounted from the case support tables3.

As shown inFIG. 2, the case support table3has guide sections6a,6bdisposed side by side at a specified interval on an upper surface. On the respective side surfaces of the guide sections6a,6b,a locking section6cis provided in a protruding state. On the surface of one guide section6a,an identification sensor7is provided. Herein, the identification sensor7uses a transmission sensor made up of plural pairs of a light emitting element and a light receiving element. The identification sensor7, as described later, is used to detect a bar code18put on the tablet storage case4and automatically identify tablets housed in the tablet storage cases4. It is to be noted that magnetic sensors such as hall ICs are also adaptable. Moreover, on the side surface of the other guide section6b,there is formed a semiconductor pattern8, which makes it possible to detect mounting and dismounting states of the tablet storage case4on and from the case support table3. Moreover, a delivery passage9is formed in the case support table3. A counting sensor10is provided on the delivery passage9, which allows counting of the passing tablets. The counting sensor10herein uses a transmission sensor made up of a light emitting element and a light receiving element. Further, a motor11which is drive-controlled in response to a control signal from an unshown control unit is housed inside the case support table3. A rotating shaft of the motor11protrudes from the top surface of the case support table3, and a protruded portion is integrated with a drive gear12. It is to be noted that the passage of electric current through the identification sensor7and the counting sensor10are controlled so that the identification sensor7and the counting sensor10are set to on state immediately after the start of mounting of the tablet storage case4on the case support table3or after passing of certain time as described later.

The tablet storage case4is almost in a box shape, and its top surface can be opened and closed with a cover article13. The upper surface of the bottom wall of the tablet storage case4is formed almost into a conical shape, in which a rotor14is disposed.

A plurality of groove-shaped pocket sections15extending in vertical direction are formed equiangularly on the external surface of the rotor14. The pocket section15has a width and a depth that allows retention of only one tablet that is stored. A rotating shaft of the rotor14protrudes from the lower surface of the bottom wall of the tablet storage case4, and is integrated with a driven gear16.

Moreover, on the bottom surface of the tablet storage case4, there are formed guide reception sections17which are guided by the guide sections6of the case support table3. On the guide reception sections17, there is respectively formed an elastic locking reception section17awhich is locked with and unlocked from the locking section6cformed on each of the guide sections6a,6b.A bar code18(equivalent to the information display section of this embodiment) detected by the identification sensor7is provided on one inner side surface of the guide reception section17. The bar code18corresponds to the kind of a tablet stored in the tablet storage case4, and information about the tablet such as the kind of the tablet is displayed on an unshown display section based on a detection result of the bar code18by the identification sensor7.

Further, on the other inner side surface of the guide reception section17, a metal plate19is electrically connected to the conductive pattern8. The metal plate19and the conductive pattern8constitute the case detection means of the present invention.?

The counting sensor10may be set to on state immediately upon contact of the metal plate19with the conductive pattern8, or may be set to on state after passing of estimated time necessary for noise influence due to external perturbations such as light from a fluorescent lamp to disappear at the time of starting mounting of the tablet storage case4on the case support table3. In the latter case, however, if tablets should be dropped off from the tablet storage cases4during a period from the start to the end of the mounting of the tablet storage cases4on the case support tables3, it is necessary that the dropped tablets can be detected by the counting sensor10.

Description is now given of the operation of the above-structured tablet feeder1.

When the tablet storage case4is dismounted from the case support table3, the metal plate19becomes out of contact with the conductive pattern8, so that the identification sensor7and the counting sensor10keep on state. This ensures prevention of erroneous detection by the identification sensor7or the counting sensor10due to external perturbations such as light from a fluorescent lamp.

When the tablet storage case4is mounted on the case support table3, as shown inFIG. 7, the conductive pattern8comes into contact with the metal plate19immediately after the start of mounting, and both the identification sensor7and the counting sensor10are set to on state. However, as described before, they may be set to on state after passing of a time during which noise is generated due to influence of external perturbations immediately after the start of mounting of the tablet storage case4on the case support table3. This makes it possible to surely detect the tablets passing through the delivery passage by the counting sensor10even when the tablet storage case4is mounted on the case support table3.

Although in the aforementioned embodiment, the case detection means is composed of a combination of the conductive pattern8and the metal plate19which is simply for obtaining electrical conduction, various means such magnetic sensors including hall elements and MR elements as well as limit switches are also applicable.

Further, in the aforementioned embodiment, the conductive pattern8and the metal plate19are set to constantly keep a conductive state immediately after the start of mounting of the tablet storage case4. However, it is also possible to structure so that with partial disconnection of the conductive pattern8for example, a state from the start of the mounting of the tablet storage case4to the middle of the mounting and a state from the middle of the mounting to the end of the mounting may be separately detected. Consequently, even if the identification sensor7as disclosed in the aforementioned embodiment is adopted, it becomes possible to prevent such failure as erroneous detection by the identification sensor7when the tablet storage case4is not fully mounted on the case support table3.