Printer, printer control method and program

1. A printer for printing on a label continuous body including a label temporarily attached to a belt-like liner, comprising:

a label detecting unit having a light-emitting portion configured to emit a detecting light and a light-receiving portion configured to receive the detecting light; and

a control unit configured to adjust a light emitting output of the detecting light in the light-emitting portion to bring (i) an output voltage from the label detecting unit when the light-receiving portion receives the detecting light through the liner without the label closer to (ii) an output voltage from the label detecting unit when the light-receiving portion receives the detecting light through a state in which there is no label continuous body between the light-emitting portion and the light-receiving portion.

2. The printer according to claim 1 , wherein:

the control unit is configured to adjust the light emitting output so that an output voltage from the label detecting unit when the light-receiving portion receives the detecting light through the liner and the label becomes a specific value.

3. The printer according to claim 2 , wherein:

the specific value is determined such that the output voltage from the label detecting unit when the detecting light is received through the liner without the label is adjusted closer to an output value from the label detecting unit when the detecting light is received through the state in which there is no label continuous body between the light-emitting portion and the light-receiving portion.

4. The printer according to claim 1 , wherein:

the control unit is configured to set a threshold value for determining an end portion of the label.

5. The printer according to claim 4 , wherein:

the control unit is configured to be able to change the threshold value.

6. The printer according to claim 5 , wherein:

the control unit is configured to set a half-value of the specific value as the threshold value.

7. The printer according to claim 1 , further comprising:

a thermal head for printing on the label; and

a platen roller disposed opposite to the thermal head to hold and feed the label continuous body between the thermal head and the platen roller, wherein;

the label detecting unit is disposed on a downstream side of the thermal head and the platen roller in the feeding direction of the label continuous body.

8. The printer according to claim 7 , further comprising:

a cover configured to cover an interior of the printer and configured to be openable and closable; and

a sensor configured to detect an opening and a closing of the cover, wherein:

the control unit is configured to cause the light-emitting portion to emit the detecting light when the cover is closed, to set the output voltage from the label detecting unit when the light receiving portion is receiving the detection light through the label and the liner as the specific value, to detect the end portion of the label while feeding the label continuous body, and to stop feeding the label continuous body after the end portion of the label is detected.

9. The printer according to claim 1 , wherein:

the control unit is configured to feed the label continuous body so that the detecting light is irradiated to a specific position of the label prior to adjusting the light emitting output.

10. The printer according to claim 9 , wherein:

the control unit is configured to irradiate a previous detecting light before the light emitting output is adjusted when irradiating the detecting light to the specific position.

11. A control method for a printer with a label detecting unit having a light-emitting portion configured to emit a detecting light and a light-receiving portion configured to receive the detecting light, the printer configured to print on a label continuous body including a label temporarily attached to a belt-like liner, the control method comprising:

adjusting a light emitting output of the detecting light in the light-emitting portion to bring an output voltage from the label detecting unit when the light-receiving portion receives the detecting light through the liner without the label closer to an output voltage from the label detecting unit when the light-receiving portion receives the detecting light through a state in which there is no label continuous body between the light-emitting portion and the light-eceiving portion.

12. The control method for the printer according to claim 11 , further comprising:

feeding the label continuous body so that the detecting light is irradiated to a specific position of the label prior to adjusting the light emitting output.

13. A computer-readable storage medium storing a program for causing a computer installed in a printer with a label detecting unit having a light-emitting portion configured to emit a detecting light and a light-receiving portion configured to receive the detecting light, the printer also configured to print on a label continuous body including a label temporarily attached to a belt-like liner wherein the computer-readable storage medium is configured to:

adjust a light emitting output of the detecting light in the light-emitting portion, and

bring an output voltage from the label detecting unit when the light-receiving portion receives the detecting light through the liner without the label closer to an output voltage from the label detecting unit when the light-receiving portion receives the detecting light through a state in which there is no label continuous body between the light-emitting portion and the light-receiving portion.

14. The computer-readable storage medium storing a program for causing the computer installed in the printer according to claim 13 , further configured to:

feed the label continuous body so that the detecting light is irradiated to a specific position of the label prior to adjusting the light emitting output.