JPH09214698A - Light receiving element mounting location adjusting mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform adjustment so that recording light may easily and accurately pass the center of the light receiving surface of a light receiving element, in addition to a writing starting location adjustment. SOLUTION: In a state that a fixing screw 21 is loosened, a movable bracket 18 is temporarily fastened. In this state, a polygon driving motor 6 is rotated and laser light is scanned. A state that the scanning surface of laser light is completely separated from a light receiving element 16 is made by turning a micrometer 28. The micrometer 28 is gradually moved from this state. After the value (x1) of the micrometer 28 in which a waveform starts to appear and the subsequent value (x2) of the micrometer 28 when the micrometer is moved till the waveform can not be observed are determined, the light receiving element 16 is adjusted to an optimum location by adjusting the micrometer 28 to the central value (x1+x2)/2 and fastening the fixing screw 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used, for example, in an image recording apparatus for performing scanning recording with a light beam, detects the passage of the light beam for each scanning, and adjusts the timing of the writing position from the detection timing. The present invention relates to a phase sensor, and more particularly to a mounting position adjusting mechanism for fixing the light receiving element at an optimum position.

[0002]

2. Description of the Related Art Generally, in an image recording apparatus for recording an image on a light-sensitive material such as a film or a photographic paper by modulating and scanning a light beam with image data, it is necessary to adjust the timing of a writing start position for each scanning. It uses a sensor.
The phase sensor has a light receiving element arranged at the end of the scanning range of the light beam, detects the passage of the light beam at each scanning by this light receiving element, and counts the pixel clock based on the detection timing. The write start position for each scan can be determined from. Therefore, the mounting position of the light receiving element of the phase sensor affects the accuracy of the writing start position, and it is necessary to adjust the position with extremely high accuracy.

As a conventional technique for solving this problem, Japanese Patent Laid-Open Publication No. 4-251814 (Prior Art 1) discloses that a scanning start position sensor functioning as the phase sensor is mounted on a movable bracket so that a writing start position can be adjusted. This eliminates the need for an electric circuit for adjusting the writing position, and the phase sensor is detachably attached to the movable bracket so that the phase sensor can be replaced and cleaned without adjustment. A scanning device "is disclosed.

That is, in this apparatus, the phase sensor is attached to a detachable bracket, and the bracket is attached to the movable bracket. The movable bracket can be moved by a long hole, and the movable bracket is temporarily fixed with a screw, and after adjusting the position, the screw is tightened and fixed.

[0005] In addition, as the prior art, Japanese Patent Laid-Open No. 61-2
No. 42160 (Prior Art 2), by moving a light receiving element in a scanning direction and a direction orthogonal to the scanning direction,
There is disclosed an "image writing synchronous light detection device" which can position a light receiving element for detecting the image writing synchronous light easily and with high accuracy and can determine an image writing timing without requiring a counter or the like.

Further, in Japanese Utility Model Application Laid-Open No. 2-41219 (Prior Art 3), the light receiving element position adjusting mechanism slides the light receiving element and the fixing mechanism fixes the fixed position of the light receiving element. There is no need to adjust the delay time, the circuit configuration of the control circuit can be simplified,
A "light beam scanning position detecting device" having improved low cost is disclosed.

However, the above-mentioned prior arts 1 to
In the configuration of the related art shown in FIG. 3, the light receiving element mounting position of the phase sensor is only adjusted, and the actual position adjustment must be performed visually. In order to actually adjust the position, it is necessary to adjust the recording light so as to pass through the center of the light receiving surface of the light receiving element. Therefore, when the recording light is infrared light that is not visible light, a special device such as an infrared scope is required, which makes adjustment very difficult. Further, even with visible light, if the amount of light is small, the adjustment becomes similarly difficult.

Even if the above problem does not occur, since the light receiving element of the phase sensor is relatively small, the recording light is visually determined by the position on the outer shape of the light receiving element of the phase sensor to determine how much margin there is at the adjusted position. However, there is a problem that it is different from the range of the specified sensitivity of the actual light receiving element. Further, since the recording light is laser light, when the power is large, visual adjustment involves the risk of blindness,
Coordinator skill is required.

[0009]

As described above, in the conventional mounting position adjusting mechanism, the main purpose is to simplify the electric circuit by adjusting the writing position. Therefore, the recording light is the light receiving surface of the light receiving element. There was not enough consideration as a subtle adjustment function for passing through the center.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and not only adjust the writing position but also adjust the recording light so that the recording light can easily and accurately pass through the center of the light receiving surface of the light receiving element. To provide.

[0011]

In order to solve the above problems, the present invention provides a light receiving element mounting position adjusting mechanism for adjusting the mounting position of a light receiving element so that scanning light passes through the center of a light receiving surface. A light-receiving element is mounted on a base, a movable bracket that can move the base vertically with respect to the scanning light, a fine movement mechanism that quantitatively finely moves the base of the movable bracket, and this fine movement mechanism. When the base of the movable bracket is moved by the measuring means for measuring the change in the peak level of the light receiving element output and the amount of movement while the light receiving surface traverses the scanning light, the measurement result obtained by this measuring means. From the optimum position determining means for determining the optimum position of the light receiving element, the position of the base is adjusted through the fine movement mechanism so that the light receiving element comes to the position determined by the optimum position determining means. It is obtained by the.

In particular, the fine movement mechanism is characterized in that the base of the movable bracket is moved by using a micrometer.

Also, the movable bracket includes an elastic member for applying an elastic force to the base in a direction perpendicular to the scanning light, and a fixing means for fixing the base when the light receiving element reaches an optimum position. The fine movement mechanism presses the base of the movable bracket against the elastic force.

Further, the optimum position discriminating means is characterized in that a range from the rise of the output of the light receiving element to the fall thereof is obtained, and the intermediate position thereof is decided as the optimum position.

[0015]

In the light-receiving element mounting position adjusting mechanism having the above structure, the signal from the light-receiving element is monitored by measurement with an oscilloscope, and the light-receiving element is gradually moved by the fine movement mechanism.
It is possible to know in what range the light receiving element responds, and finally position the light receiving element at the center position between the adjustment value of the fine movement mechanism where the light receiving element starts receiving light and the adjustment value of the fine movement mechanism where the light receiving element does not respond. If adjustment is done, the adjustment ends.

The above method eliminates the need for any visual adjustment, and solves all the problems of difficulty in adjustment because there is no adjustment margin, the risk of blindness, and no fine movement mechanism.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing the configuration of an embodiment of a laser scanning recording apparatus to which the present invention is applied.

In the figure, 1 is a semiconductor laser,
Laser light emitted from the semiconductor laser 1 is adjusted to parallel light by a collimator lens 2, narrowed down by a condenser lens 3, and guided to a polygon mirror 5 by a reflection mirror 4. The polygon mirror 5 is rotated at a constant speed by the polygon drive motor 6, and the laser light is reflected by the fθ lens 7 in a form of being swung left and right.

The fθ lens 7 serves to keep the moving speed of the laser light constant, and passes through the reflection mirror 8 and the recording paper 9
Are scanned and recorded. The recording paper 9 is attracted to the moving table 10, and an image can be recorded by moving the moving table 10. The moving table 10 is fixed to the feed screw 11, and is moved in the sub scanning direction by the sub scanning motor 12.

A laser beam is detected for each scan using a phase sensor so that the writing timing of each scan does not shift due to optical factors such as the rotation accuracy of the polygon drive motor 6 and the surface accuracy of the polygon mirror 5. It is necessary to make adjustments so that the data is written out after a fixed time from the time of detection. Therefore, the reflection mirror 13 guides the laser light to the phase sensor unit 14 arranged beside the moving table 10.

In this embodiment, the phase sensor unit 14 is adjusted by the laser beam scanning surface 1 before adjustment as shown in FIG.
5 does not coincide with the center of the light receiving surface of the light receiving element 16. Therefore, it is necessary to move the light receiving element 16 so that the scanning surface 15 passes through the center position 17 of the light receiving surface. To that end, FIG.
The light receiving element 16 is attached to the movable bracket 18 shown in FIG.

The movable bracket 18 has a base 20 and an elongated hole 2
It is attached with four fixing screws 21 through 2.
Further, the spring 27 of the movable bracket 18 and the shaft 23 of the micrometer 28 can be moved left and right. The micrometer 28 is fixed to the fixing bracket 24 with screws 2
The fixing bracket 24 is fixed to the base 20 with screws 26.

The actual adjustment procedure will be described with reference to FIGS. 3 to 5.

First, the four fixing screws 21 for fixing the movable bracket 18 are temporarily loosened and temporarily fixed to make the movable bracket 18 move. Next, the polygon drive motor 6 is rotated to scan the laser light. The micrometer 28 is rotated so that the scanning plane of the laser beam is completely deviated from the light receiving element 16 (position x0 in FIG. 4).
When the output waveform of the light receiving element 16 at that time is viewed with an oscilloscope (not shown), since the scanning light is not hit,
Naturally, the waveform is as shown in FIG.

When the light receiving element 16 is moved by gradually rotating the micrometer 28 in this state, the light receiving surface of the light receiving element 16 is scanned with laser light and a waveform is observed on the oscilloscope (b to d in FIG. 4). ). When the peak value of the waveform when the light receiving element 16 is gradually moved by using the micrometer 28 in this way is plotted, as shown in FIG.
The level is detected at the position of x1, and the level cannot be detected at the position of x2. From this waveform, it can be seen that the center position between x1 and x2 is the most stable position that can be detected.

Therefore, the value x1 of the micrometer 28 when the light receiving element 16 is removed from the scanning surface is gradually moved by the micrometer 28 and a waveform starts to appear.
After that, after obtaining the value x2 of the micrometer 28 when it is moved until the waveform cannot be observed, the micrometer 28 is adjusted to the central value (x1 + x2) / 2 and the four fixing screws By tightening 21, the light receiving element 16 can be adjusted to the optimum position.

As described above, according to the present invention, the light receiving element of the phase sensor is mounted on the movable bracket, and the movable bracket is moved by the fine movement device such as a micrometer. It can be judged safely and quantitatively. Further, the fine movement device is provided, so that the adjustment becomes easy.

[0029]

As described above, according to the present invention, there is provided a light receiving element mounting position adjusting mechanism capable of not only adjusting the writing position but also adjusting the recording light so as to easily and accurately pass through the center of the light receiving surface of the light receiving element. Can be provided.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a laser scanning recording apparatus provided with this mechanism as an embodiment of a light receiving element attachment position adjusting mechanism according to the present invention.

FIG. 2 is a diagram for explaining a shift of a scanning surface with respect to the light receiving element of the same embodiment.

FIG. 3 is a diagram showing a configuration of a light receiving element fine movement mechanism of the same embodiment.

FIG. 4 is a waveform chart showing an output waveform of a light receiving element of the same embodiment.

FIG. 5 is a diagram showing the relationship between the position of the light receiving element and the peak of the output waveform of the light receiving element in the same embodiment.

[Explanation of symbols]

 1 Semiconductor Laser 2 Collimator Lens 3 Condenser Lens 4 Reflection Mirror 5 Polygon Mirror 6 Polygon Drive Motor 7 fθ Lens 8 Reflection Mirror 9 Recording Paper 10 Moving Table 11 Feed Screw 12 Sub-scanning Motor 13 Reflection Mirror 14 Phase Sensor 15 Laser Light Scanning Surface 16 Light receiving element 17 Light receiving surface center position 18 Movable bracket 20 Base 21 Fixing screw 22 Long hole 23 Micrometer shaft 24 Fixing bracket 25, 26 Screw 27 Spring 28 Micrometer

Claims (4)

[Claims] 1. A light receiving element mounting position adjusting mechanism for adjusting a mounting position of a light receiving element so that scanning light passes through the center of a light receiving surface, wherein the light receiving element is mounted on a base and the base is mounted on the base. A movable bracket that is movable in the vertical direction to the scanning light, a fine movement mechanism that quantitatively finely moves the base of the movable bracket, and the light receiving surface when the base of the movable bracket is moved by this fine movement mechanism. A measuring means for measuring the change in the peak level of the light receiving element output and the amount of movement while the scanning light crosses the scanning light; and an optimum position determining means for determining the optimum position of the light receiving element from the measurement result obtained by this measuring means. A light receiving element mounting position adjusting mechanism, comprising: adjusting the position of the base through the fine movement mechanism so that the light receiving element is located at the position determined by the optimum position determining means. 2. The light receiving element mounting position adjusting mechanism according to claim 1, wherein the fine movement mechanism moves a base of the movable bracket by using a micrometer. 3. The movable bracket includes an elastic member that applies an elastic force to the base in a direction perpendicular to the scanning light, and a fixing unit that fixes the base when the light receiving element reaches an optimum position. The light receiving element mounting position adjusting mechanism according to claim 1, wherein the fine movement mechanism presses and moves the base of the movable bracket against the elastic force. 4. The light receiving element according to claim 1, wherein the optimum position determining means obtains a range from a rise of the light receiving element to a fall of the output, and determines an intermediate position thereof as an optimum position. Mounting position adjustment mechanism.