Lighting circuit

1. An automotive lamp comprising:

a light source comprising a plurality of N (N represents an integer of 2 or more) light-emitting elements electrically coupled in series and spatially arranged in a horizontal direction; and

a lighting circuit structured to drive the light source,

wherein the lighting circuit comprises:

a bypass switch circuit comprising a plurality of N bypass switches each of which is coupled in parallel to a corresponding one of the plurality of N light-emitting elements;

a constant current driving circuit structured to supply a driving current stabilized to a target current to the light source; and

a light distribution controller structured to control the bypass switch circuit,

wherein, when a duty ratio is determined for each of the plurality of N light-emitting elements for a given light distribution pattern, two light-emitting elements form a control unit such that a sum total of the duty ratios thereof is equal to or otherwise smaller than 100%,

and wherein the light distribution controller is structured to switch on and off the plurality of N bypass switches such that the two light-emitting elements included in the same control unit do not turn on at the same time,

wherein the plurality of N light-emitting elements are arranged in a horizontal direction, and are classified into a first group, a second group, a third group, and a fourth group, such that they are sequentially arranged from a given end,

wherein one light-emitting element included in the first group is paired with one light-emitting element included in the third group,

wherein one light-emitting element included in the second group is paired with one light-emitting element included in the fourth group,

and wherein two bypass switches that correspond to each pair of the light-emitting elements form a pair.

2. The automotive lamp according to claim 1 , wherein the light distribution pattern can be switched and selected from among a plurality of light distribution patterns,

and wherein, with the maximum duty ratio (%) of the i-th (1≤i≤N) light-emitting element for all the light distribution patterns as D MAXi , two or more light-emitting elements form a control unit such that the sum total of the maximum duty ratios thereof is equal to or smaller than 100%.

3. An automotive lamp comprising:

a light source comprising a plurality of N (N represents an integer of 2 or more) light-emitting elements electrically coupled in series and spatially arranged in a horizontal direction; and

a lighting circuit structured to drive the light source,

wherein the lighting circuit comprises:

a bypass switch circuit comprising a plurality of N bypass switches each of which is coupled in parallel to a corresponding one of the plurality of N light-emitting elements;

a constant current driving circuit structured to supply a driving current stabilized to a target current to the light source; and

a light distribution controller structured to control the bypass switch circuit,

wherein, when a duty ratio is determined for each of the plurality of N light-emitting elements for a given light distribution pattern, two light-emitting elements form a control unit such that a sum total of the duty ratios thereof is equal to or otherwise smaller than 100%,

and wherein the light distribution controller is structured to switch on and off the plurality of N bypass switches such that the two light-emitting elements included in the same control unit do not turn on at the same time,

wherein the plurality of N light-emitting elements are arranged in the form of a pair of an upper array and a lower array each extending in a horizontal direction,

wherein two or more light-emitting elements positioned in a central region of the lower array are classified as a first group,

wherein two or more light-emitting elements positioned on both sides of the lower array are classified as a second group,

wherein two or more light-emitting elements positioned in the upper array are classified as a third group,

wherein one light-emitting element included in the first group is paired with one light-emitting element included in the third group,

wherein one light-emitting element included in the second group is paired with one light-emitting element included in the second group,

and wherein two bypass switches that correspond to the pair of the light-emitting elements form a pair.

4. An automotive lamp comprising:

a light source comprising a plurality of N (N represents an integer of 2 or more) light-emitting elements electrically coupled in series and spatially arranged in a horizontal direction; and

a lighting circuit structured to drive the light source,

wherein the lighting circuit comprises:

a bypass switch circuit comprising a plurality of N bypass switches each of which is coupled in parallel to a corresponding one of the plurality of N light-emitting elements;

a constant current driving circuit structured to supply a driving current stabilized to a target current to the light source; and

a light distribution controller structured to control the bypass switch circuit,

wherein, when a duty ratio is determined for each of the plurality of N light-emitting elements for a given light distribution pattern, two light-emitting elements form a control unit such that a sum total of the duty ratios thereof is equal to or otherwise smaller than 100%,

and wherein the light distribution controller is structured to switch on and off the plurality of N bypass switches such that the two light-emitting elements included in the same control unit do not turn on at the same time,

wherein the bypass switch circuit is structured as an integrated circuit,

and wherein, with a forward voltage of each of the light-emitting elements as V F , and with a number of the plurality of light-emitting elements as N, the bypass switch circuit has a breakdown voltage that is lower than (V F ×N).

5. An automotive lamp comprising:

a light source comprising a plurality of N (N represents an integer of 2 or more) light-emitting elements electrically coupled in series and spatially arranged in a horizontal direction; and

a lighting circuit structured to drive the light source,

wherein the lighting circuit comprises:

a bypass switch circuit comprising a plurality of N bypass switches each of which is coupled in parallel to a corresponding one of the plurality of N light-emitting elements;

a constant current driving circuit structured to supply a driving current stabilized to a target current to the light source; and

a light distribution controller structured to control the bypass switch circuit,

wherein, when a duty ratio is determined for each of the plurality of N light-emitting elements for a given light distribution pattern, two light-emitting elements form a control unit such that a sum total of the duty ratios thereof is equal to or otherwise smaller than 100%,

and wherein the light distribution controller is structured to switch on and off the plurality of N bypass switches such that the two light-emitting elements included in the same control unit do not turn on at the same time,

wherein the light distribution pattern can be switched and selected from among a plurality of light distribution patterns,

and wherein two or more light-emitting elements that form each of the control units are recombined for each light distribution pattern.

6. A driving method for driving a light source included in an automotive lamp, comprising:

providing the light source comprising a plurality of N (N represents an integer of 2 or more) light-emitting elements electrically coupled in series, and spatially arranged in a horizontal direction;

providing a bypass switch circuit comprising a plurality of N bypass switches each of which is coupled in parallel to a corresponding one from among the plurality of light-emitting elements;

supplying a driving current stabilized to a target current to the light source;

determining a duty ratio of each of the plurality of N light-emitting elements for a given light distribution pattern, and forming two light-emitting elements as a control unit such that a sum total of the duty ratios thereof is equal to or smaller than 100%; and

switching on and off the bypass switch circuit such that two bypass switches that correspond to two light-emitting elements included in the same control unit are not turned off at the same time, wherein the light distribution pattern can be switched and selected from among a plurality of light distribution patterns,

and wherein two or more light-emitting elements that form each of the control units are recombined for each light distribution pattern.