JPH04107214U - image head - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent warpage of the lens array in the center of the image head and use an inexpensive and high-precision housing. [Configuration] At the center of the lens array 4, leaf springs 16, 1
A height fine adjustment means 6 which is a combination of a screw 8 and a screw 20 is provided to finely adjust the height of the central part of the lens array. Further, a side plate 8 is provided separately from the head base 2 and head cover 30, and the lens array 4 is positioned using screws 24 and leaf springs 26. Since the head base 2 and the head cover 30 have no protrusions along the longitudinal direction, they can be manufactured with high precision at low cost by drawing metal.

Description

[Detailed explanation of the idea]

0001

[Field of application of idea]

This idea is suitable for image heads such as light emitting diode printer heads and image sensors. Regarding the prevention of image quality deterioration due to warping, especially in the center of the lens array, and and simplification of the design structure.

0002

[Prior art]

The basic structure of an image head is that a housing has a light emitting/receiving element and a lens array arranged at a predetermined distance. They are installed at intervals, and the light receiving and emitting elements are light emitting elements such as light emitting diode arrays. A light-receiving element such as a photodiode array, photocell array, etc. is used. Also the house Normally, both the head base and head cover are used for the head cover. The important thing here is is the distance between the light receiving and emitting elements and the center position along the height direction of the lens array, and the distance between the light receiving and emitting elements and the center position along the lens array height direction. The goal is to maintain a constant distance between the center position of the array and the light source or photosensitive drum.

0003 In the conventional example, the lower ends of both ends of the lens array were attached to the reference plane provided on the housing. and position the bottom surfaces of both ends of the lens array. However, lens arrays are expensive. There is a warp along the horizontal direction (optical axis direction), and if you only position both ends, the central part cannot be adjusted. Out of focus. This warpage reaches a maximum of about 0.2 mm, for example, and causes a shift in focus. This is a major cause. Also, the object to be aligned is originally inside the lens array. At the core position, not at the lower end of the lens array. This is the center line of the lens array. This is because the focal point is determined by the distance from the light receiving/emitting element, the photosensitive drum, etc. lens array There is a variation of about ±0.4 mm in height (length in the optical axis direction), and the lens array When the lower end is positioned, the variation in length in the optical axis direction directly affects the focus accuracy. It appears.

0004 Another problem is that it is difficult to obtain the shape accuracy of the housing. subordinate In the next model, both ends of the housing are held against the lower end of the lens array. Housings are also required at the ends. For this reason, the manufacturing method for the housing is inexpensive and precise. High-grade extraction cannot be used. To solve this problem, the shape of the housing Make it uniform along the longitudinal direction of the lens array and light receiving and emitting elements, and avoid protrusions and depressions. It is necessary to clean it.

[0005]

[Problems to be devised]

The challenge with this idea was to prevent the deterioration of focus accuracy due to warpage in the center of the lens array. There are many things.

[0006]

[Structure of the idea]

This idea is based on the idea that the elongated lens array and the light receiving and emitting elements are arranged in a housing with a predetermined interval. In the image head attached to the lens array, a light receiving and emitting light is placed in the center of the long lens array. The present invention is characterized in that an adjustment means is provided for finely adjusting the distance between the elements.

[0007] Preferably, side plates are provided at both ends of the housing. This side plate is provided separately from the lens and is fixed to the housing. Support the array.

[0008] If an adjustment means for fine adjustment of the position is provided in the center of the lens array, the center It can solve the problem of warpage and improve the image formation of light from the image head in, for example, TV cameras. If you make fine adjustments while monitoring the condition, it will work fine regardless of the height variation of the lens array. It can be assembled in such a way that a correct image can be obtained. Separate from housing If side plates are provided, the housing can be removed by removing the protrusions on both ends of the housing and pulling it out. can be manufactured. As a result, an inexpensive and high quality housing can be obtained. rhinoceros The dowel plate is preferably provided with means for finely adjusting the position of the lens array, and In addition to fine adjustment, the position of the lens array is finely adjusted at three points. Here said TV When combined with optical image detection using a camera, etc., high-quality images can be obtained. .

[0009]

【Example】 The structure of the embodiment will be explained with reference to FIGS. 1 to 5. Figure 1 shows the view from the head base side. The overall structure is shown, and in the figure 2 is made of aluminum and formed by drawing. 4 is the lens held between the head base 2 and the head cover on the back side. 6 is an adjustment means for finely adjusting the height of the central part of the lens array 4; 8 is an adjustment means for finely adjusting the height of the central portion of the lens array 4; side plate, 10 is a board on which light emitting diode array 12 is mounted, 14 is external A control circuit for the light emitting diode array 12 and the like are mounted on the board. light emitting diode array In place of A 12, a photodiode array, a photovoltaic cell array, or the like may be used. center Three leaf springs are used as the position adjustment means 6, and the center leaf spring 16 is used as the lens array. 4 from above (from the right in the figure), and press the left and right leaf springs 18 from below (from the left in the figure). the lens array 4. 20 is a fine adjustment screw that presses the center leaf spring 16 to adjust the position. Make fine adjustments to the position. The side plate 8 is made of synthetic resin, for example, and is attached to the head with screws 22. Attach the lens array 4 to the board base 2, position the bottom surface of both ends of the lens array 4 with the screws 24, and A spring 26 presses the lens array 4 from above. 28 is for attaching the image head It is a protrusion.

0010 FIG. 2 shows the leaf spring 16 of the center adjusting means 6, and FIG. 3 shows the left and right leaf springs 18. Indicates the minute. In the figure, 30 is the head cover, which is made of aluminum like the head base 2. Manufactured by drawing out aluminum. The lens array 4 is made of rod-shaped material such as synthetic resin or glass. Lenses 32, 32 are hardened in two rows with synthetic resin 34, 34, and the rod-shaped lens 32 may be arranged in one column, or may be arranged in three or more columns. The important thing for positioning is the rod shape. At the center position of the lens 32 (the center position along the optical axis direction of the lens 32), The height of the ray 32 (length in the optical axis direction) varies by product by about ±0.4 mm. Also, since it is soft after being hardened with synthetic resin 34, the center part of about 0.2 mm There is a warp. Therefore, the upper end of the lens array 4 is connected to a leaf spring 16, and the lower end is connected to a leaf spring 18. 18, finely adjust these positions with the screws 20, and connect the lens array 4 and light emitting diode. The distance between the lens array 12 and the lens array 12 should be substantially the same, and the lens array 12 should be placed in the correct position. Hold A4. In addition, the leaf springs 18, 16, 18 are made by bending a single metal plate. It shall be made into one piece with a spring.

[0011] FIG. 4 shows a side view of the image head, and FIG. 5 shows the structure of the side plate 8. Figure 4 As shown in FIG. Attach it to both ends to block it and prevent the intrusion of dust, etc. Also, 36 in Figure 4 is , a flexible printed circuit board for connection with the external board 14. As shown in Figure 5 Then, fix the side plate 8 to the head base 2 with the pan head machine screws 22, and then secure it with the screws 24. The lower end of the lens array 4 is positioned and pressed from above with the leaf spring 26.

0012 The assembly process of the embodiment will be explained. The head base 2 and head cover 30 are elongated. It has no protrusions along its length and can be manufactured by drawing metal. this Taking advantage of this fact, an inexpensive and highly accurate head base 2 and head cover 30 are manufactured. Since the head base 2 and head cover 30 are made of metal, they are susceptible to heat deformation and humidity. No swelling. Set the board 10 on the head base 2, and attach the flexible printed circuit board. After connecting to the external board 14 with 36, the head cover 30, lens array 4, side Set plate 8 etc. The side plate 8 is made of synthetic resin and is made by injection molding etc. Since it is molded, even complex shapes can be easily manufactured, and high-precision products are used locally. As shown in FIG. 5, fix the side plate 8 to the head base 2 with screws 22, and Position both ends of the lower surface of the lens array 4 with the screws 24, and press with the plate springs 26. Hold. Similarly, finely adjust the position of the center part of the lens array 4 with the screw 20, and 16 from above, and leaf spring 18 from below to hold it.

[0013] In these processes, for example, as shown in FIG. 6, a height sensor 38 is used to measure the height in advance. While measuring the height of the upper end of the lens array 4 that has been sorted and grouped, Adjust with screws 24 and 20 so that the height of the ends is uniform. Or as shown in Figure 7. uni, a television camera 40 monitors the optical image from the lens array 4 at three locations: at both ends and at the center. and make fine adjustments using the screws 24 and 20 to bring it into focus. As a result, the lens array A4 is positioned at three locations, at both ends and the center, to prevent the effects of warping, etc. can be held in the correct position with uniform spacing. Furthermore, head base 2 The head cover 30 and head cover 30 may be integrated from the beginning, or the height of the center part may be adjusted. The adjusting means 6 may be any suitable means as long as it can finely adjust the height of the central portion of the lens array 4. can be used.

[0014]

[Effect of the idea]

This idea prevents the image quality from deteriorating due to warpage in the center of the lens array. can be done

[Brief explanation of drawings]

[Fig. 1] Front view of the image head of the embodiment

[Fig. 2] Enlarged cross-sectional view of the main part of the central part of the image head of the embodiment

[Fig. 3] Enlarged cross-sectional view of the main parts of the image head of the example at the center left and right positions

[Fig. 4] Enlarged side view of the image head of the embodiment.

[Fig. 5] Enlarged front view of the main parts of the image head of the example with the head cover removed.

FIG. 6 is a front view showing the adjustment process of the lens array of the image head of the example.

FIG. 7 is a front view showing a modification of the adjustment process of the lens array of the image head of the embodiment.

[Explanation of symbols]

2 Head base 4 Lens array 6 Adjustment means for finely adjusting the height of the central part 8 Side plate 12 Light emitting diode array 14 External board 16, 18, 26 leaf spring 20, 24 screw

Claims (1)

[Scope of utility model registration request] Claim 1: In an image head in which an elongated lens array and a light emitting/receiving element are arranged side by side in a housing at a predetermined interval, a lens is provided in the center of the elongated lens array for finely adjusting the spacing between the emitting and receiving elements. An image head, characterized in that it is provided with adjustment means.