JPS63177033A - Method and apparatus for measuring light emitting diode head - Google Patents

Abstract

PURPOSE:To measure a large number of LED arrays within a short measuring time, by arranging CCD arrays equipped with a large number of CCDs arranged side by side so that each CCD is opposed to each LED array of an LED head. CONSTITUTION:CCD arrays 12 are arranged in front of an LED head at a predetermined interval and the same number of CCDs as the LED arrays are arranged to the CCD arrays 12 in opposed relation to the LED arrays of the LED head. Each LED array of the LED head 1 is turned on and off by an LED driving circuit 11 and the CCD arrays 12 are connected to a CCD driving circuit 13 and CCD corresponding to the specific LED array allowed to light is brought to a light quantity measuring state. The analogue data of the quantity of the emitted light from the LED array measured by CCD is converted to digital data by an A/D converter 14 to be stored in a host computer 10. The data of the irregularity of the light receiving sensitivity of CCD is corrected by the host computer 10.

Description

Detailed Description of the Invention [In the field of industrial application, the present invention relates to a light emitting diode head that measures the amount of light emitted from each light emitting diode array in a light emitting diode head used for optical writing in a printer using an electrophotographic process. This invention relates to a measuring method and a measuring device.

[Conventional technology]

In general, a light emitting diode (hereinafter abbreviated as LED) head has a large number of LED arrays arranged in an array and a Rufoc lens array (hereinafter abbreviated as SLA) that is placed opposite to these LED arrays. ), but when such an LEr) head is used for printing light in a printer, if there is variation in the amount of light emitted from each LED array, this variation in the amount of light emitted directly affects the print quality. Since this leads to deterioration, it is necessary to measure the light emission of each LED array first to detect whether the variation in the amount of light emitted by the LED array is within a reference range (usually ±15%).

For this reason, conventionally, t as shown in FIG. 3 and FIG.
-F I) Head measuring device was used.

This conventional L [+] head measuring device is shown in FIG. It has measurement units 1 to 4 each having an objective lens 5 facing to the measuring unit 1-4. A camera 7 that receives light from the objective lens 5 and an optical power meter 8 that receives light from the objective lens 5 via a half mirror 6 are integrally provided. The measurement unit 4 is moved by a pulse stage 9 in three directions, X-Y and 7, so as to be able to be finely adjusted. Moreover, the movement of this pulse stage 9 is as shown in FIG.
This is done using a control signal from 0.

This boss! - The computer 10 has the LED head 1
The LED drive circuit 11 is connected to the LFD head 1 to avoid blinking a specific LED array. ing. Furthermore, the host computer 10 is provided with a measurement signal (
data) is to be input, and this data is to be stored in the host 1-computer 10.

1 of the LED head 1 with the above-described configuration. FI
) To detect the dispersion of the emitted light ω of the array, first,
l The FD head 1 is fixed to a support stand (not shown), and then the measurement unit 4 is moved by the pulse stage 9 to a position where the light from the LED array at one end forms an image on the camera 7 via the objective lens 5. . Then, the control signal from the host computer 10 lights up the LED array through which the light can be imaged on the camera 7 via the LED driving vJ circuit 11, and the amount of light emitted is converted into optical power through the half mirror 6. The light reaches the meter 8, and the optical power meter 8 measures the emitted light ω. When the measurement of one LED array was completed in this way, this LEr was turned off, and the pulse stage 9 was used to move the measurement unit l- so that the objective lens 5 was directed towards the next LED array by λ1. 4 in the direction of the arrow and perform the same measurements as described above.

[Problem that the invention seeks to solve]

However, in the conventional light emitting diode head measuring method and measuring device described above, only one L E
The measurement unit 4 must be moved to position the objective lens 5 each time the D array is measured, which takes a long time to measure. It took about two hours. Therefore, there is a problem in that the inspection cannot keep up when producing a large number of LED heads 1.

An object of the present invention is to provide a method and apparatus for measuring a light emitting diode head that can overcome the problems of the conventional methods and measure a large number of LED arrays in a short measurement time. shall be.

[Means for solving problems]

The method for measuring an LED head of the present invention is to measure the emitted light Φ of each LED array of a light emitting diode head, which is constituted by a large number of LED arrays arranged in a row and an SL eight arranged opposite to these LED arrays. In the method for measuring an ED head, a CCD array including a large number of charge-coupled devices (hereinafter abbreviated as CCr) arranged in an array is arranged so that each CCD faces each IEr) array, Each 1-FD is blinked in sequence according to the a and lI signals 8 from the host combination coater, and the corresponding 16 COD receives the light from the LED when lit, measures the gloss, and sends this measured data to the host computer. It is characterized by being able to be entered and memorized.

Furthermore, the LED head measuring device of the present invention measures the amount of light emitted from each LED array of an LED head, which is composed of a large number of LED arrays arranged in a row and SLAs arranged opposite to these IFD arrays. In the measuring device for the LED head to be measured, each CCD has a CCD array having a large number of CODs arranged in an array.
An LED array driving circuit arranged to face the array and for blinking each of the arrays is connected to the LFD head, and a CCD driving circuit for making each COD ready for first measurement is connected to the CCD. An analog-to-digital converter 1 connected to the array and connected to the CCD drive circuit to convert analog data measured by each COD into digital data! A-D'! I converter and the CCD drive circuit,
The device is characterized in that it is connected to a host computer that outputs control signals to the CCD drive circuit and stores data from the AD converter.

[For production]

According to the method and apparatus for measuring a light emitting diode head of the present invention, since the CCD array is placed opposite to the LED head and the emitted light of each 1-ED array of the iED head is measured, the emitted light is measured for each LED array. It is possible to measure the entire LED array of one LED head in a short measurement time without having to take the trouble of moving and determining the position of the measurement device.

〔Example〕

The present invention will be explained below with reference to embodiments shown in the drawings. Note that the same configurations as those of the conventional device described above are designated by the same reference numerals 1 and 1 in the drawings, and the explanation of 1 is omitted.

Figures 1 and 2 show examples of the measuring device for light emitting diode heads according to the present invention;
As shown in FIG. 1, a CCD array 12 is disposed in front of the L[D head 1 at a predetermined interval. This C
The CD array 12 includes 1-ED heads 1, E
The same number of C arrays as the L E D arrays are placed opposite the D arrays.
The distance between the LED head 1 and the CCD array 12 described above is 5 from the LED array.
The LED head 1 and the CCD are arranged so that the light irradiated through the LA 3 forms an image on the corresponding COD.
It is set on a substrate (not shown) sandwiched between the arrays 12.

As shown in FIG. , t CCD drive circuit 13
C corresponding to the specific LED array connected to and illuminated.
Light a CD? It is designed to be in measurement state. The COD drive circuit 13 is also connected to an A-D converter 14, which converts the analog data of the light emitted from the LEr) array measured by the COD into digital data. It's starting to look like J°. Further, the Δ-r converter 14 is connected to a host computer 10, etc., and the A-r) converter 1
The host computer 10 stores and overwrites the data outputted by the computer 4. Also, this host computer 1
0 is connected to the LFD drive circuit 11, and the [
[I) 1) A certain LED array of the head 1 is made to blink.

By the way, each CCO of the CCr) array 12 may have variations in light receiving sensitivity, but if the CCD array 12 is equipped with CODs with varying light receiving sensitivities, then the El
) If the luminous intensity of each LED array of the head 1 is measured, the measurement data will be inaccurate. Therefore, first, each one of the LED heads 1 whose light emitting light intensity of each LED array is known is
- The amount of light emitted from the ED array is determined by each C of the CCD array 12.
If there is an error between the measured data and the actual light emitting product of each LED array when measured using a CD, the data on the variation in light receiving sensitivity of the COD is input to the 11-st computer 10 and the host computer 10 reads the data. Make it possible to correct the measurement data, and make sure that the measurement data is COD in advance.
Make sure that it is not affected by the light-receiving sensitivity of

Next, the measuring method of the present invention will be explained using the above-described configuration.

First, the ED head 1 is fixed to a support stand (not shown) or in front of the ED head 1, and the light irradiated from each ED array described above through the SLA 3 is imaged onto the corresponding COD. The CCI) array 12 is arranged at intervals such that the LED drive circuit 11 lights the LE[) array at one end of the LEO head 1 according to a control signal from the host computer 10. The CCD corresponding to the array is enabled to receive light by a control signal sent from the Δ/I to ST computer 10 via the Δ-reverse converter 14, and the CCD measures the light emitted from the LED array. And this measurement data is C
The data is input from the OD drive circuit 13 to the Δ-D converter 14 as analog data, where it is digitally transformed and input to the host computer 10.
Stored at 0.

When the measurement of the light emitted from one LED array is completed in this way, this LED array is turned off in response to a command signal V3 from the host computer 10, and the next IFD array is turned on instead. Same as above 1
Measurements are made using the culm, and this process is repeated to measure the 2560 L E D heads installed in one L E D head 1.
Measurements of the ED array can be made.

According to the embodiment described above, each L of the L E D head 1
Since the CCD array 12 equipped with a COD corresponding to the ED array is installed opposite to the LED head 1 and the emitted light fi1 of the LED array is measured, unlike the conventional method described above, each measurement of one LED array is performed. This eliminates the trouble of moving and positioning the measurement unit 4 (FIG. 4), and therefore high-speed measurement can be achieved.

Note that the present invention is not limited to the embodiments described above, and various changes can be made as necessary.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to measure a large number of LED arrays in a short measurement time, and
Suitable for inspection when producing heads in large quantities.

[Brief explanation of the drawing]

1 and 2 show an embodiment of a measuring device for a light emitting diode head according to the present invention, in which FIG. 1 is a perspective view of the mechanical configuration, FIG. 2 is a control circuit diagram, 3aj and 4 show a conventional measuring device for a light emitting diode head, FIG. 3 is a perspective view of the mechanical configuration, and FIG. 4 is a control circuit diagram. 1... L E O head, 2... Gauging, 3...
...S l-Δ, 4...Measurement unit 1-15...Objective lens, 6...Half mirror, 7...Camera, 8
...Optical power meter, 9...Pulse stage, 10
. . . host 1-] monitor, 11 . . . FD drive circuit, 12 . . . CCD array, 13 . Applicant's agent Shunsuke Nakao No. 1vA Figure 2

Claims (1)

[Claims] 1) Measuring the amount of light emitted from each light emitting diode array of a light emitting diode head composed of a large number of light emitting diode arrays arranged in an array and a SELFOC lens array arranged opposite to these light emitting diode arrays. In a method for measuring a light-emitting diode head, a charge-coupled device array including a large number of charge-coupled devices arranged in an array is arranged such that each charge-coupled device faces each light-emitting diode array, and control signals from a host computer are provided. The light emitting diodes are sequentially turned on and off, and the light from the light emitting diodes when lit is received by the corresponding charge-coupled device to measure the amount of light, and the measured data is input to the host computer and stored. A method for measuring a light emitting diode head characterized by: 2) The data measured by the charge-coupled device is analog data, and the analog data is input to the host computer via an analog-to-digital converter. How to measure light emitting diode head. 3) The host computer is adapted to perform sensitivity correction of each charge-coupled device.
The method for measuring a light emitting diode head according to item 1 or 2. 4) Measurement of the light emitting diode head, which measures the amount of light emitted from each light emitting diode array of the light emitting diode head, which is composed of a large number of light emitting diode arrays arranged in a row and a SELFOC lens array arranged opposite to these light emitting diode arrays. A light-emitting diode drive circuit in which a charge-coupled device array including a large number of charge-coupled devices arranged in an array is arranged such that each charge-coupled device faces each light-emitting diode array, and the light-emitting diode drive circuit blinks each light-emitting diode array. is connected to the light-emitting diode head, and a charge-coupled device drive circuit is connected to the charge-coupled device array to enable each charge-coupled device to measure the amount of light. An analog-to-digital converter that converts measured analog data to digital data is connected, and a control signal is output to the charge-coupled device drive circuit and the analog-to-digital conversion is performed to the analog-to-digital converter and the charge-coupled device drive circuit. A measuring device for a light emitting diode head, characterized in that it is connected to a host computer that stores data from the device. 5) The host computer is adapted to perform sensitivity correction of each charge-coupled device.
A measuring device for a light emitting diode head as described in Section 1.