JPH0289663A - Device for correcting quantity of light of optical array - Google Patents

Abstract

PURPOSE:To prevent the generation of the unevenness of recording density by composing the title compensator of a photoconductor receiving the light of an optical array, a photocurrent detection means detecting the photocurrents of the photoconductor and a light-quantity correction means keeping the quantity of light of the optical array constant by photocurrents detected by the photocurrent detection means. CONSTITUTION:When a device power supply is turned ON, a photocurrent detection permissible signal is generated, and charge by a charger 13 and exposure by an optical array 2 are repeated only by the total number section of the detection light-emitting elements of the optical array 2 when a photocurrent detection period is started. The photocurrents of a photoconductor 1 are detected by a photocurrent detection circuit 4, a recording permissible signal is generated when the detection of the photocurrents of the total number of the optical array 2 is completed, and recording operation is started. A drive signal is output to a drive circuit 6 so that the quantities of light of each light-emitting element of the optical array 2 are kept constant from the relationship of the photocurrents detected by a light-quantity correction circuit 5 and the light-emitting elements of the optical array 2, and the optical array 2 is driven. The photoconductor conducts the operation of the formation of a latent image on recording working.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical array recording device in which a plurality of light emitting elements are arranged, and in particular to a light intensity correction device for an optical array that has a simple configuration and is suitable for highly accurate light intensity correction. Regarding.

[Conventional technology]

A conventional optical array light amount correction device is disclosed in Japanese Patent Application Laid-Open No. 561560.
As described in No. 71, the entire optical array is turned on using the time when data is not transferred to the optical array, and this light is converted into voltage by a photoelectric conversion means that receives the light as reflected light from the photoreceptor drum surface. The amount of light from the optical array was corrected to a constant level by controlling the driving current or driving time of the optical array based on the voltage.

[Problem to be solved by the invention]

The above conventional technology does not take into consideration the fact that if there is a discrepancy in the sensitivity wavelength characteristics of the light receiving element and the photoconductor drum, uneven recording density will occur even if the light intensity of the optical array is corrected to be constant. , the number of photodetectors required corresponds to the number of optical arrays, so as the recording width increases or the recording density increases, the photodetectors become more expensive, and the correction accuracy may be affected by reflectance due to the color of the photoconductor or dirt on the surface. There is a difficulty.

An object of the present invention is to provide a light amount correction device for an optical array that has a simple configuration and performs highly accurate light amount correction.

[Means to solve the problem]

The above object includes a photoconductor that receives light from an optical array, a photocurrent detection means that detects a photocurrent of the photoconductor, i'iij
This is achieved by a light amount correcting device for an optical array, which includes a light amount correcting means for making the light amount of the optical array constant using a photocurrent detected by a photocurrent detection means.

[Effect]

The photoconductor receives light from the optical array, the photocurrent detection means detects the photocurrent of the photoconductor, and the light amount correction means makes the amount of light from the optical array constant using the photocurrent detected by the photocurrent detection means. works. As a result, since the photoconductor performs the functions of forming a latent image during actual recording and receiving light from the optical array, there is no deviation in the sensitivity wavelength characteristics that would occur if a separate light-receiving element is provided, and recording density unevenness is avoided. There is no occurrence of

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. 1st
The figure is an overall configuration diagram of an optical array recording device including an optical array light amount correction device showing an embodiment of the present invention. 1 is a photoconductor drum that forms a latent image and receives light from the optical array 2; 2 is an optical array; 3 is a rod lens; 4 is a photocurrent detection circuit that detects the photocurrent of the photoconductor 1; 5 is a light A light amount correction circuit that keeps the light amount of the optical array 2 constant based on the photocurrent detected by the current detection circuit 4; 6 is a drive circuit for the optical array 2; 7 is a developing device; 8
1 is a recording paper, 9 is a transfer charger, 1o is a fixing device, 11 is a cleaner, 12 is an erase lamp, and 13 is a charger.

The operation of FIG. 1 configured as above will be explained using the time chart of FIG. 2. When the device is powered on, the device power ON signal (a) is inverted and the photocurrent detection permission signal (
b) occurs. When entering the photocurrent detection period, the charger 13
Charging (t2) and exposure (t3) by the optical array 2 are repeated for all the light emitting elements of the optical array 2. Since the peak value of the photocurrent (f) of the photoconductor 1 changes depending on the amount of light from the optical array 2, variations in the amount of light can be found by measuring the peak value of the photocurrent (f). The photocurrent of the photoconductor 1 is detected by a photocurrent detection circuit 4 for all the light emitting elements of the optical array 2. When photocurrent detection for all the optical arrays 2 is completed, that is, when the photocurrent detection period t1 ends, a recording permission signal (O) is generated and an actual recording operation begins.

When the actual recording operation starts, the light amount correction circuit 5 adjusts the light amount of each light emitting element of the optical array 2 to be constant based on the relationship between the photocurrent detected during the photocurrent detection period 11 and the light emitting elements of the optical array 2. , outputs a drive signal to the drive circuit 6. Drive circuit 6
drives the optical array 2 based on the drive signal from the light amount correction circuit 5.

Note that during the recording operation, the photoconductor performs the operation of forming a latent image.

Since the photocurrent detection of the photoconductor 1 by the optical array 2 described above is repeated every time the device is turned on, it is possible to cope with changes in the amount of light from the optical array 2 over time.

The photocurrent detection circuit 4 shown in FIG. 1 will be explained in more detail with reference to FIG. 14 is a changeover switch that selects whether or not to detect the photocurrent of the photoconductor 1 using the photocurrent detection permission signal 17; 15 is a resistor that converts the photocurrent into a voltage 18 proportional to the photocurrent when detecting the photocurrent; 16 is a photocurrent This is a peak value detection circuit that detects the peak value of voltage 18 proportional to . When the photocurrent detection permission signal 17 shown in FIG. 2 is input, the changeover switch 14 is connected to the A side, and the photocurrent of the photoconductor 1
It flows to 5. The peak value of a voltage 18 proportional to the photocurrent generated on the opposite side of the resistor 15 from the ground is detected by a peak value detection circuit 16, and outputted as a peak value detection value 19 to the light amount correction circuit 5 in FIG. The peak value detection circuit 16 is reset each time the light emitting elements of the optical array 2 are switched (signal shown in FIG. 2(d)), and outputs a voltage 18 proportional to the amount of light from each light emitting element. On the other hand, when the photocurrent detection is completed, the changeover switch 14 is connected to the B side in preparation for forming a latent image during recording.

The light amount correction circuit 5 shown in FIG. 1 will be explained in more detail with reference to FIG. 4. 20 is A that converts the voltage 18 (analog value) proportional to the amount of light of each light emitting element of the optical array 2 into a digital voltage 23;
/D converter, 21 is memory, 22 is light amount correction calculation ROM
It is. A voltage 18 proportional to the amount of light output from the photocurrent detection circuit 4 shown in FIG. 3 is converted into a digital signal 23 by an A/D converter 20 and written into a memory 21. memory 2
1 has a storage capacity equal to n times the number of light emitting elements in the optical array 2 (n is the number of bits of the digital signal 23), and is only used for writing when photocurrent is detected (period tl in Fig. 2(b)). become. When the photocurrent detection is completed, the memory 21 becomes read-only, and the light amount correction calculation ROM 22 outputs the light amount correction value 24 so that the light amount of each light emitting element of the optical array 2 becomes constant. Light intensity correction value 24 of the output of the light intensity correction calculation ROM 22
is input to the drive circuit 6 to control the drive current or drive time.

According to this embodiment, there is no need to separately provide a light receiving element for detecting the amount of light from the optical array 2 and a photoconductor for forming a latent image, and since the same photoconductor can be used, it is possible to use the same photoconductor. There is no recording density unevenness due to deviations in sensitivity wavelength characteristics, and highly accurate light amount correction is possible.

Another embodiment of the present invention will be described with reference to FIG.

FIG. 5 is an overall configuration diagram of an optical array recording apparatus including an optical array light amount correction device showing another embodiment of the present invention. 1 is a photoconductor drum that forms a latent image, 2 is an optical array, 3 is a rod lens, 25 is a surface potential detection circuit that detects the surface potential of the photoconductor 1, and 5 is a surface detected by the surface potential detection circuit 25. A light amount correction circuit that keeps the light amount of the optical array 2 constant based on the electric potential; 6 is a drive circuit for the optical array 2; 7 is a developing device; 8 is a recording paper; 9 is a transfer charger; 10 is a fixing device; 11 is a cleaner; 1 is an erase lamp, and 13 is a charger.

The operation of FIG. 5 configured as above will be explained using the time chart of FIG. 6. When the device is powered on, the device power ON signal (a) is inverted and a surface potential detection permission signal (h) is generated. When the surface potential detection period begins, charging (tz) by the charger 13 and exposure (t3) by the optical array 2 begin.
) is repeated for all the light emitting elements of the optical array 2. Since the fall of the surface potential (g) of the photoconductor 1, that is, the slope of the light attenuation due to exposure of the optical array 2 (shi 3) changes depending on the amount of light from the optical array 2, the surface potential (g) of the photoconductor 1 ) By measuring the slope (falling edge), you can find out the variation in light intensity. The surface potential of the photoconductor 1 is detected by the surface potential detection circuit 25 for all the light emitting elements of the optical array 2. When the surface potential detection of all the optical arrays 2 is completed, that is, the surface potential detection period t1 is completed.

A recording permission signal (c) is generated and the actual recording operation begins.

When the actual recording operation starts, the light amount correction circuit 5 adjusts the light amount of each light emitting element of the optical array 2 to be constant based on the relationship between the surface potential detected during the surface potential detection period tl and the light emitting elements of the optical array 2. , outputs a drive signal to the drive circuit 6. The drive circuit 6 controls the optical array 2 based on the drive signal from the light amount correction circuit 5.
to drive.

According to this embodiment, the amount of light from the optical array 2 can be measured as the surface potential of the photoconductor that performs the function of forming a latent image.
When used separately, recording density unevenness due to deviations in wavelength characteristics of sensitivity does not occur, and highly accurate light amount correction can be performed.

〔Effect of the invention〕

According to the present invention, since the photoconductor drum can perform two functions: light reception for detecting the amount of light from the optical array and formation of a latent image during actual recording, the wavelength characteristics of the photosensitivity that occur when performing the two functions. There is no unevenness in recording density due to misalignment, and highly accurate light amount correction is possible.

Furthermore, the configuration of the device is simpler than when a light receiving element for detecting the amount of light from the optical array is separately provided.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of an optical array recording device including an embodiment of the optical array light amount correction device of the present invention, FIG. 2 is a time chart showing the operation of each part of FIG. 1, and FIG. FIG. 4 is a detailed configuration diagram of the photocurrent detection circuit shown in FIG. 1, FIG. 4 is a detailed configuration diagram of the light amount correction circuit shown in FIG. 1, and FIG. 5 is an optical array recording including another embodiment of the optical array light amount correction device of the present invention. FIG. 6, which is an overall configuration diagram of the apparatus, is a time chart showing the operation of each part in FIG. 1. Photoconductor tram, 2.. Optical array, 4.. Photocurrent detection circuit, 5.. Light quantity correction circuit, 6.. Optical array drive circuit, 25.. Surface potential detection circuit. (f) -r Mayu 1 吋 1 〱ふTurtle-''\-j'u----u Funeral map Funeral map Figure 6 2 Piro convex love squid ryoλ-f\-1, go.

Claims (1)

[Scope of Claims] 1. In an optical array recording device in which a plurality of light emitting elements are arranged, a photoconductor that receives light from the optical array, photocurrent detection means that detects a photocurrent of the photoconductor, and the photocurrent 1. A light amount correcting device for an optical array, comprising a light amount correcting means for making the light amount of the optical array constant based on the photocurrent detected by the detection means. 2. A light amount correction device for an optical array, wherein the photoconductor according to claim 1 is a photoconductor that forms a latent image. 3. The light amount of the optical array, wherein the photocurrent detection means according to claim 1 detects the photocurrent by lighting the optical arrays one by one using the time when no image signal is transferred to the optical array. correction device. 4. A light amount correction device for an optical array, wherein the photocurrent detection means according to claim 1 is provided with a switching means for switching between photocurrent detection and latent image formation in response to a photocurrent detection permission signal. 5. A light amount correcting device for an optical array, wherein the light amount correcting means according to claim 1 corrects the amount of light by controlling a drive current of the optical array. 6. A light amount correcting device for an optical array, wherein the light amount correcting means according to claim 1 corrects the amount of light by controlling the drive time of the optical array.