Electronic flash apparatus for conserving flash battery life

Claim 2

In an improved electronic flash unit of the type including a flashtube having (1) a normal non-conductive state and (2) a conductive state, a flashtube firing capacitor for storing an electrical potential to render said flashtube conductive, means for charging said firing capacitor, and monitor means responsive to the charge on said firing capacitor (1) for operably coupling a source of electrical potential to said firing capacitor when the charge on said firing capacitor is below a predetermined level and (2) for effectively de-coupling such electrical potential source from said charging means when the charge on said firing capacitor is above said predetermined level, the improvement comprising: means for automatically disabling said monitor means after a time interval during which said flashtube is maintained in its non-conductive state.

Claim 3

In an improved electronic flash unit of the type including a flashtube having (1) a normal non-conductive state and (2) a conductive state, a flashtube firing capacitor for applying an electrical potential to said flashtube to render saidd flashtube conductive, means for charging said firing capacitor, and monitor means responsive to the charge on said firing capacitor (1) for operably coupling said firing capacitor charging means to a source of electrical potential when the charge on said firing capacitor is below a predetermined level and (2) for de-coupling said firing capacitor charging means from the electrical potential source when the charge on said firing capacitor is above said predetermined level, the improvement comprising: means for automatically preventing said monitor means from coupling said capacitor charging means to the electrical potential source after a time interval during which said flashtube remains in its non-conductive state.

Claim 4

In an improved electronic flash unit of the type including a flashtube having (1) a normal non-conductive state and (2) a conductive state, a flashtube firing capacitor for applying an electrical potential to said flashtube to render saidd flashtube conductive, means for charging said firing capacitor, and monitor means responsive to the charge on said firing capacitor (1) for operably coupling said firing capacitor charging means to a source of electrical potential when the charge on said firing capacitor is below a predetermined level and (2) for de-coupling said firing capacitor charging means from the electrical potential source when the charge on said firing capacitor is above said predetermined level, the improvement comprising: means for automatically preventing said monitor means from coupling said capacitor charging means to the electrical potential source after a time interval during which said flashtube remains in its non-conductive state.

Claim 5

In an improved electronic flash unit of the type including a flashtube having (1) a normal non-conductive state and (2) a conductive state, a flashtube firing capacitor for applying an electrical potential to said flashtube to render said flashtube conductive, means for charging said firing capacitor, means for coupling said capacitor charging means to a source of electricl potential to enable said firins capacitor to be charged, and monitor means responsive to the charge on said firing capacitor (1) for operably coupling said firing capacitor charging means to the electrical potential source when the charge on said firing capacitor is below a predetermined level and (2) for de-couping said firing capacitor charging means from the electrical potential source when the charge on said firing capacitor is above said predetermined level, the improvement comprising: a. means for counting the number of times said monitor means couples said firing capacitor charging means to the electrical potential source; and b. means controlled by said counting means when said counting means reaches a given count value for effectively overriding said monitor means to prevent said capacitor charging means from being coupled to the electrical potential source.

Claim 6

In an improved electronic flash unit of the type including a flashtube having (1) a normal non-conductive state and (2) a conductive state, a flashtube firing capacitor for applying an electrical potential to said flashtube to render said flashtube conductive, means for charging said firing capacitor, means for coupling said capacitor charging means to a source of electricl potential to enable said firins capacitor to be charged, and monitor means responsive to the charge on said firing capacitor (1) for operably coupling said firing capacitor charging means to the electrical potential source when the charge on said firing capacitor is below a predetermined level and (2) for de-couping said firing capacitor charging means from the electrical potential source when the charge on said firing capacitor is above said predetermined level, the improvement comprising: a. means for counting the number of times said monitor means couples said firing capacitor charging means to the electrical potential source; and b. means controlled by said counting means when said counting means reaches a given count value for effectively overriding said monitor means to prevent said capacitor charging means from being coupled to the electrical potential source.

Claim 7

In an improved electronic flash unit of the type including a flashtube having (1) a normal non-conductive state and (2) a conductive state, a flashtube firing capacitor for applying an electrical potential to said flashtube to render said flashtube conductive, means for charging said firing capacitor, means for coupling said capacitor charging means to a source of electrical potential to enable said firing capacitor to be charged, and monitor means responsive to the charge on said firing capacitor (1) for operably coupling said firing capacitor charging means to the electrical potential source when the charge on said firing capacitor is below a predetermined level and (2) for de-coupling said firing capacitor charging means from the electrical potential source when the charge on said firing capacitor is above said predetermined level, the improvement comprising: a. means for counting the number of times said monitor means couples said firing capacitor charging means to the electrical potential source; b. means controlled by said counting means when said counting means reaches a given count value for effectively overriding said monitor means to prevent said capacitor charging means from being coupled to the electrical potential source; and c. means for resetting said counting means in response to said flashtube assuming said conductive state.

Claim 8

In an improved electronic flash unit of the type including a flashtube having (1) a normal non-conductive state and (2) a conductive state, a flashtube firing capacitor for applying an electrical potential to said flashtube to render said flashtube conductive, means for charging said firing capacitor, means for coupling said capacitor charging means to a source of electrical potential to enable said firing capacitor to be charged, and monitor means responsive to the charge on said firing capacitor (1) for operably coupling said firing capacitor charging means to the electrical potential source when the charge on said firing capacitor is below a predetermined level and (2) for de-coupling said firing capacitor charging means from the electrical potential source when the charge on said firing capacitor is above said predetermined level, the improvement comprising: a. means for counting the number of times said monitor means couples said firing capacitor charging means to the electrical potential source; b. means controlled by said counting means when said counting means reaches a given count value for effectively overriding said monitor means to prevent said capacitor charging means from being coupled to the electrical potential source; and c. means for resetting said counting means in response to said flashtube assuming said conductive state.

Claim 9

In an improved electronic flash unit of the type including a flashtube having (1) a normal non-conductive state and (2) a conductive state, a flashtube firing capacitor for applying an electrical potential to sid flashtube to render said flashtube conductive, means for charging said firing capacitor, means for coupling said capacitor charging means to a source of electrical potential to enable said firing capacitor to be charged, and monitor means responsive to the charge on said firing capacitor (1) for operably coupling said firing capacitor charging means to the electrical potential source when the charge on said firing capacitor is below a predetermined level and (2) for de-coupling said firing capacitor charging means from the electrical potential source when the charge on said firing capacitor is above said predetermined level, the improvement comprising: a. means for counting the number of times said monitor means couples said firing capacitor charging means to the electrical potential source; b. means controlled by said counting means when said counting means reaches a given count value for effectively overriding said monitor means to prevent said capacitor charging means from being coupled to the electrical potential source; and c. actuatable switch means for resetting said counting means independent of the count value of said counting means.

Claim 10

In an improved electronic flash unit of the type including a flashtube having (1) a normal non-conductive state and (2) a conductive state, a flashtube firing capacitor for applying an electrical potential to sid flashtube to render said flashtube conductive, means for charging said firing capacitor, means for coupling said capacitor charging means to a source of electrical potential to enable said firing capacitor to be charged, and monitor means responsive to the charge on said firing capacitor (1) for operably coupling said firing capacitor charging means to the electrical potential source when the charge on said firing capacitor is below a predetermined level and (2) for de-coupling said firing capacitor charging means from the electrical potential source when the charge on said firing capacitor is above said predetermined level, the improvement comprising: a. means for counting the number of times said monitor means couples said firing capacitor charging means to the electrical potential source; b. means controlled by said counting means when said counting means reaches a given count value for effectively overriding said monitor means to prevent said capacitor charging means from being coupled to the electrical potential source; and c. actuatable switch means for resetting said counting means independent of the count value of said counting means.

Claim 11

In an improved electronic flash unit of the type including a flashtube having (1) a normal non-conductive state and (2) a conductive state, a flashtube firing capacitor for applying an electrical potential to said flashtube to render said flashtube conductive, means for charging said firing capacitor, and means for coupling said capacitor charging means to a source of electrical potential to enable said firing capacitor to be charged, the improvement comprising: a. circuit means for producing a time-delay signal a predetermined time interval after the charge on said firing capacitor reaches a predetermined level; and b. means responsive to said time-delay signal for effectively de-coupling said capacitor charging means from the electrical potential source.

Claim 12

In an improved electronic flash unit of the type including a flashtube having (1) a normal non-conductive state and (2) a conductive state, a flashtube firing capacitor for applying an electrical potential to said flashtube to render said flashtube conductive, means for charging said firing capacitor, and means for coupling said capacitor charging means to a source of electrical potential to enable said firing capacitor to be charged, the improvement comprising: a. circuit means for producing a time-delay signal a predetermined time interval after the charge on said firing capacitor reaches a predetermined level; and b. means responsive to said time-delay signal for effectively de-coupling said capacitor charging means from the electrical potential source.

Claim 13

In an improved electronic flash unit including a flashtube having (1) a normal non-conductive state and (2) a conductive state, a trigger circuit for applying a trigger signal to said flashtube, a flashtube firing capacitor for applying a discharge signal to said flashtube in response to the occurrence of said trigger signal to render said flashtube conductive, means for charging said firing capacitor, the improvement comprising: a. switch means having (1) a normal first state for coupling said capacitor charging means to a source of electrical potential to enable said firing capacitor to be charged, and (2) an energizable second state for effectively de-coupling said charging means from the electrical potential source; b. circuit means for producing a time-delay signal a predetermined time interval after the charge on said firing capacitor reaches a predetermined level; c. means for applying said time-delay signal to said switch means to switch said switch means into its second state; and d. means responsive to said trigger signal for applying a control signal to said circuit means to prevent the occurrence of said time-delay signal.

Claim 14

In an improved electronic flash unit including a flashtube having (1) a normal non-conductive state and (2) a conductive state, a trigger circuit for applying a trigger signal to said flashtube, a flashtube firing capacitor for applying a discharge signal to said flashtube in response to the occurrence of said trigger signal to render said flashtube conductive, means for charging said firing capacitor, the improvement comprising: a. switch means having (1) a normal first state for coupling said capacitor charging means to a source of electrical potential to enable said firing capacitor to be charged, and (2) an energizable second state for effectively de-coupling said charging means from the electrical potential source; b. circuit means for producing a time-delay signal a predetermined time interval after the charge on said firing capacitor reaches a predetermined level; c. means for applying said time-delay signal to said switch means to switch said switch means into its second state; and d. means responsive to said trigger signal for applying a control signal to said circuit means to prevent the occurrence of said time-delay signal.

Claim 15

In an improved electronic flash unit of the type including a flashtube having (1) a normal non-conductive state and (2) a conductive state, a flashtube firing capacitor for applying an electrical potential to said flashtube to render said flashtube conductive, means for charging said firing capacitor, and means for coupling said capacitor charging means to a source of electrical potential to enable said firing capacitor to be charged, the improvement comprising: a. circuit means for producing a control signal a predetermined time interval after the charge on said firing capacitor reaches a predetermined level; b. means responsive to said control signal for effectively de-coupling said capacitor charging means from the electrical potential source; and c. means for initiating operation of said circuit means in timed relation with said firing capacitor being charged to said predetermined level.

Claim 16

In an improved electronic flash unit of the type including a flashtube having (1) a normal non-conductive state and (2) a conductive state, a flashtube firing capacitor for applying an electrical potential to said flashtube to render said flashtube conductive, means for charging said firing capacitor, and means for coupling said capacitor charging means to a source of electrical potential to enable said firing capacitor to be charged, the improvement comprising: a. circuit means for producing a control signal a predetermined time interval after the charge on said firing capacitor reaches a predetermined level; b. means responsive to said control signal for effectively de-coupling said capacitor charging means from the electrical potential source; and c. means for initiating operation of said circuit means in timed relation with said firing capacitor being charged to said predetermined level.