JPH0818191A - Printed board and led - Google Patents

Abstract

PURPOSE:To emit light with the same luminance from individual LEDs or individual blocks of LEDs by varying the resistance on a wiring pattern depending on which of opposing pairs of land is short-circuited thereby regulating the load current. CONSTITUTION:The printed board comprises a wiring board 10, wiring patterns P1-P3, Q1-Q3 for mounting LED lamps D1-D9, and jumper parts J1-J9 including lands L1-L9 and opposing lands M1-M9. When light is emitted from individual blocks of LED lamps D1-D3, D4-D6, D7-D9, resistances on the wiring patterns P1 and Q1, P2 and Q2, and P3 and Q3 of respective blocks B1-B3 are varies. Since the load current is regulated by short-circuiting a desired pair of lands, individual LEDs or individual blocks thereof can emit light with the same illuminance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a printed circuit board and an LED.
The present invention relates to an apparatus, for example, a printed circuit board for mounting an LED array, a printed circuit board used for other general assembly products; an LED display device such as an automobile stop lamp having an LED lamp mounted on the printed circuit board, and a copying machine. The present invention relates to a reading LED light source used, an eraser LED light source, and an LED device such as an LED print head used in a printer or a facsimile.

[0002]

2. Description of the Related Art A conventional printed circuit board and LED device will be described by taking an example of an automobile stop lamp shown in FIGS. This stop lamp is printed circuit board 1
Nine LED lamps D1 to D9 are linearly mounted on the top, and the circuit configuration is three blocks (that is,
It is divided into a first block B1, a second block B2 and a third block B3). In the first block B1, the chip resistor r1 is connected to the LED lamps D1 to D3 by soldering to a land (not shown) of a wiring pattern on the printed board 1. Similarly, for the second block B2, the chip resistors r2 are connected to the LED lamps D4 to D6, and for the third block B3, the chip resistors r3 are connected to the LED lamps D7 to D9. The power source 2 is connected to the takeout terminals T1 and T2.

It is desirable that all the blocks B1 to B3 emit light with the same brightness, but the brightness may not be uniform in block units due to variations in individual performance of the LED lamps D1 to D9. Therefore, in order to check whether or not all the blocks B1 to B emit light with the same brightness, the brightness of the stop lamp after assembly is measured using the brightness measuring device 5 including the optical sensor 3 and the recorder 4 shown in FIG. . The brightness measurement is performed by sequentially scanning the lighted LED lamps D1 to D9 with the optical sensor 3 positioned at a constant interval in the array direction and recording the output of the optical sensor 3 with the recorder 4.

If the brightness is not uniform, the chip resistance r1
By replacing one or two of r3 to r3 with different resistance values, the value of the current flowing through the LED lamps D1 to D9 causing the uneven brightness is changed.
In this way, the LED lamps D1 to D3, D4 to D6, D7
By finely adjusting the current flowing through to D9, the brightness of all the blocks B1 to B3 is made uniform.

[0005]

However, when the number is large, the replacement work of the chip resistors r1 to r3 must be repeated 3 to 4 times, which causes a problem that it is complicated and troublesome. Such a problem is not limited to the LED device such as the stop lamp. If the conventional printed circuit board is used to adjust the current flowing to a plurality of loads by exchanging the chip resistance for the conventional printed circuit board, the work is inevitably complicated. And this is a cause of increasing the cost of the product.

The present invention has been made in view of the above circumstances, and a first object thereof is to provide a printed circuit board capable of adjusting a current flowing through a load. A second object of the present invention is to provide an LED device including a plurality of LEDs, wherein the LEDs individually or in block units emit light with the same brightness.

[0007]

In order to achieve the first object, a printed circuit board according to the present invention is provided with a first wiring pattern for mounting a load, and a predetermined portion of the first wiring pattern. Is provided with a plurality of resistance printing portions in a scattered manner so as to form part of the first wiring pattern,
At least one end of each of the resistance printing units is connected to each land of the jumper unit, and the other wiring of each jumper unit facing the land is connected to the second wiring pattern, which short-circuits any pair of facing land. It is characterized in that the resistance value on the wiring pattern changes depending on whether or not.

In order to achieve the above second object, the LED device according to the present invention is such that the printed circuit board has an LE as a load.
It has a configuration in which D is provided.

[0009]

According to the structure of the printed circuit board of the present invention, the resistance value on the wiring pattern varies depending on the land pair to be short-circuited. Therefore, before the assembly is completed, the land pair is short-circuited with a probe pin to check the output of the load. Therefore, an appropriate resistance can be selected for the load. The same applies to the currents flowing in the loads respectively provided in the plurality of wiring patterns. By selecting an appropriate resistance in each wiring pattern, the currents flowing in the loads provided in the respective wiring patterns are respectively Can be adjusted. L as a load on the printed circuit board
If the ED is provided, the current flowing through the LED mounted on each wiring pattern can be adjusted by selecting the resistor.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A printed circuit board and a stop lamp according to embodiments of the present invention will be described below with reference to the drawings. The same parts and corresponding parts as those of the conventional example (FIGS. 5 and 6) and the same parts and corresponding parts between the embodiments are designated by the same reference numerals and detailed description thereof will be omitted.

As shown in FIGS. 1 and 2, the printed circuit board includes a wiring board 10, first wiring patterns P1 to P3 for mounting the LED lamps D1 to D9, and second wiring patterns Q1 to Q3. , Resistance printing units R1 to R9, lands L1 to L9, and lands M1 respectively facing them
.About.M9 and jumper portions J1 to J9. The wiring patterns P1 to P3, Q1 to Q3; the resistance printing portions R1 to R9 and the like are formed on one surface of the wiring board 10 by printing, but they may be formed on both surfaces of the wiring board 10 as necessary. .

By providing the LED lamps D1 to D9 as a load on this printed circuit board, nine LED lamps D are provided on the printed circuit board as in the conventional example (FIGS. 5 and 6).
A stop lamp for an automobile in which 1 to D9 are linearly mounted is configured. Then, as shown in FIG. 2, light emission is performed by using three LED lamps D1 to D3, D4 to D6, and D7 to D9 as one block. In addition, in FIG.
The first block B1 of the three blocks B1 to B3
Is shown.

Resistance printing units R1 to R3, R4 to R6, R7
.. to R9 are provided in predetermined portions of the wiring patterns P1 to P3 so as to form a part of the wiring patterns P1 to P3, and each of the resistance printing units R1 to R3, R4 to R6, R.
At least one end of 7 to R9 has jumper portions J1 to J3.
Lands L1 to L3 and L4 of J4 to J6 and J7 to J9
It is connected to L6, L7 to L9. All resistance printing part R1
Each of the resistance printing units R1 to R9 has a resistance value of 100Ω, but the resistance printing units R1 to R9 have different resistance values.
3, R4 to R6, R7 to R9 may be formed in combination for each block. In addition, the resistance printing units R1 to R9
Is formed by directly performing carbon printing on the wiring substrate 10, but the resistance printing portions R1 to R9 may be formed by not only carbon printing but also polysilicon deposition or the like.

Lands L1 to L3, L4 to L6, L7 to L
Jumper parts J1 to J3 and J4 to J facing 9
6, other lands M1 to M3, M4 to M6 of J7 to J9
The wiring patterns Q1 to Q3 are connected to M7 to M9, and which land pair L1 and M1 and L2 and M2 facing each other are connected.
..., the blocks B1 to B1 depending on whether L9 and M9 are short-circuited
B3 wiring patterns P1 and Q1, P2 and Q2, P3
And the resistance value on Q3 is changed.

With respect to the printed circuit board on which the LED lamps D1 to D9 are mounted, the blocks B1 to B3 described above are provided.
The unevenness of the luminance of is confirmed by the following luminance measurement.
First, connect the power supply 2 (FIG. 5) to the takeout terminals T1 and T2,
A probe pin (not shown) attached to the brightness measuring device 5 (FIG. 5) is applied to the jumper parts J2, J5, J8 to short-circuit the land pairs L2 and M2, L5 and M5, L8 and M8. As a result, the resistance value on the wiring patterns P1 and Q1, P2 and Q2, P3 and Q3 of each block B1 to B3 becomes 200Ω. As described above, the brightness is measured by the brightness measuring device 5, and the brightness of each of the blocks B1 to B3 is divided into three, "dark", "normal", and "bright".

As shown in Table 1, an appropriate resistance value is determined from the obtained brightness of each block, and the jumper portions J1 to J3 and J4 to J having the resistance value due to the short circuit of the land pair.
6, J7 to J9 are determined. That is, when the brightness is “dark”, the LED lamp D1 is reduced by lowering the resistance value.
~ Increases the current flowing through D3, D4 to D6, D7 to D9. For that purpose, the resistance value is set to 100Ω by short-circuiting the land pairs L3 and M3, L6 and M6, L9 and M9 of the jumper portions J3, J6 and J9. When the brightness is “normal”, the resistance value of 200Ω at the time of measurement is appropriate, and therefore the land pairs L2 and M2, L5 and M5, L8 and M8 of the jumper parts J2, J5 and J8 are short-circuited. When the brightness is "bright", LE is increased by increasing the resistance value.
The current flowing through the D lamps D1 to D3, D4 to D6, D7 to D9 is reduced. For that purpose, the jumper part J1,
The resistance value is set to 300Ω by short-circuiting the land pairs L1 and M1, L4 and M4, L7 and M7 of J4 and J7.

[0017]

[Table 1]

Land pair L1 and M1, L2 and M2, ..., L
A short circuit between 9 and M9 is performed by soldering and fixing a chip resistor r0 of 0Ω to the jumper parts J1 to J9 as shown in FIG. The lands L1 and M1, L2 and M
2, ..., If the distance between L9 and M9 is narrowed, lands L1 and M1, L2 can be formed only by soldering without using a chip resistor of 0Ω.
, M2, ..., L9 and M9 can be connected.

It is more preferable to use the lands L1 to L9 and M1 to M9 having a comb-like structure as shown in FIG. 3 (b). This makes it easier to short circuit by soldering,
It becomes possible to make the connection more easily by using only the solder. This is also effective for cost reduction.

By making it possible to select an appropriate resistance value of each block B1 to B3 as described above, it is possible to confirm the variation in the brightness of each block of the LED lamps D1 to D9 before the assembly is completed. Therefore, it is possible to complete the assembly at once without replacing the chip resistance of the finished product as in the conventional case. That is, in the assembly, the orthogonality rate, which was 10 to 20% in the related art, can be brought close to 100% according to the present embodiment. It should be noted that, if the input material is 100, x is a perfect non-defective product that can be obtained without modification, y is an incomplete non-defective product that is a good product if it is modified, and z is a completely defective product that is not a good product even if it is modified. The direct rate here is x%, and the yield is
It is represented by (x + y)%.

As described above, the three wiring patterns P1 and Q1, P2 and Q2, P3 and Q3 are formed by the shorted land pairs L1 and M1, L2 and M2, ..., L9 and M9.
Since the upper resistance value changes, as shown in Table 1, if an appropriate resistance is selected by short-circuiting the land pair, each wiring pattern P
LED lamps D1 to D3, D mounted on 1 to P3
The currents flowing in 4 to D6 and D7 to D9 can be adjusted respectively. And each LED lamp D1-D3, D
The LED lamps D1 to D3 of the blocks B1 to B3 are adjusted by adjusting the currents flowing in the blocks 4 to D6 and D7 to D9.
3, D4 to D6 and D7 to D9 can be made to emit light with the same brightness.

The load is not limited to the LED lamp. That is, a plurality of first wiring patterns for mounting a load are provided, and a plurality of resistance printing portions are provided so as to form a part of the first wiring pattern in a predetermined portion of each first wiring pattern. At least one end of each resistance printing section is connected to each land of the jumper section, and the other wiring of each jumper section facing the land is connected to the second wiring pattern. According to the printed circuit board configured such that the resistance value on each wiring pattern changes depending on whether the circuit is short-circuited, the current flowing through the load mounted on each of the plurality of wiring patterns can be adjusted. Therefore, it is possible to make the outputs of the loads mounted on each of the plurality of wiring patterns the same. As a result, the complexity of the work such as the replacement of the chip resistor can be avoided, and the cost of the product can be reduced.

FIG. 4 is a circuit diagram of another embodiment according to the present invention. In this embodiment, the LED lamps D1 to D9 are not divided into blocks, and each LED lamp D1 to D9 is provided with three resistance printing units R1 to R3, ..., R25 to R27. That is, in the embodiment shown in FIG.
While the resistance value can be selected for each of the divided blocks B1 to B3, the resistance value can be selected for each of the LED lamps D1 to D9 in the embodiment of FIG. Therefore, according to this embodiment, it is possible to adjust the brightness of each of the LED lamps D1 to D9 one by one.

[0024]

As described above, according to the printed circuit board of the present invention, the current flowing through the load can be adjusted by short-circuiting the desired land pair. For example, if an LED is mounted as the load, a plurality of LEDs
It is possible to realize an LED device including the LED, in which the LEDs emit light with the same brightness individually or in block units.

[Brief description of drawings]

FIG. 1 is a plan view schematically showing a main part of an embodiment of the present invention.

FIG. 2 is a circuit diagram of the embodiment shown in FIG.

FIG. 3 is a plan view showing a specific example of a jumper section used in the embodiment of FIG.

FIG. 4 is a circuit diagram showing another embodiment of the present invention.

FIG. 5 is a perspective view schematically showing an appearance configuration and a luminance measuring device of a conventional example.

FIG. 6 is a circuit diagram showing a conventional example.

[Explanation of symbols]

 R1 to R27 ... Resistance printing section J1 to J27 ... Jumper section L1 to L27 ... Land M1 to M27 ... Land P1 to P9 ... First wiring pattern Q1 to Q9 ... Second wiring pattern D1 to D9 ... LED lamp 10 ... Wiring substrate

Claims (2)

[Claims] 1. A first wiring pattern for mounting a load is provided, and a plurality of resistance printing portions are formed in a predetermined portion of the first wiring pattern in a scattered manner to form a part of the first wiring pattern. At least one end of each resistance printing portion is connected to each land of the jumper portion, and another land of each jumper portion facing the land is connected to the second wiring pattern and faces each other. A printed circuit board characterized in that the resistance value on the wiring pattern changes depending on which land pair is short-circuited. 2. An LED device comprising an LED as a load on the printed circuit board according to claim 1.