JPS63280263A - Image reader - Google Patents

Abstract

PURPOSE:To easily replace a light source by fitting a light source loading/ unloading part for loading/unloading a light source to the case body of an image reader. CONSTITUTION:In the image reader for radiating light from the light source 9 to an object to be read out and converting the light from the object to be read out into an electric signal by a photoelectric converter to read out the object to be read out, the light loading/unloading part 16 for loading/unloading the light source 9 is fixed to the case body of the reader. A light source unit 31 consisting of a blacket 7, the light source 9, a temperature keeping heater 23, a reflector 8, and sockets 30, 30 can be ejected from the light source loading/ unloading part 16. The light source 9 is disconnected from the blacket 7 by lifting it upward and freed by removing the heater 23, so that the light source 9 can be easily replaced.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to an image reading apparatus applied to, for example, a digital copying machine, an electronic file device, or a document reading device used as an input means for a personal computer. Concerning improvements to equipment.

(Prior Art) In recent years, black-and-white or color original reading devices (document scanners) have been used as, for example, digital copying machines, electronic file devices, or input means for personal computers.

Typically, this type of image reading device reads the object by irradiating light from a light source onto an object to be read, such as a manuscript, and converting the light from the object into an electrical signal using a photoelectric converter. The structure is as follows.

Further, in image reading apparatuses for color originals, a fluorescent lamp is often used as the light source because it can emit light in a wide range of wavelengths. Fluorescent lamps are suitable for reading color originals as described above because they can provide a certain degree of freedom in light emitting characteristics due to their phosphors. However, on the other hand, they tend to deteriorate significantly over time and must be replaced frequently.

For this reason, conventionally, the glass plate constituting the object placement section on which the object to be read is placed was made removable, and after the glass plate was removed, the light source could be replaced by removing the screws that fixed it. The structure is as follows.

(Problems to be Solved by the Invention) However, in the conventional configuration, it is necessary to remove the screws fixing the light source after removing the glass plate constituting the object placement section. However, there was a problem in that the task of replacing the light source was extremely troublesome and time consuming, and the user could not easily replace it.

The present invention has been made based on the above circumstances, and an object thereof is to provide an image reading device that has a simple configuration and allows for extremely easy replacement of the light source. .

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, the present invention irradiates an object to be read with light from a light source and performs photoelectric conversion of the light from the object. In an image reading device that reads the object by converting it into an electric signal with a device, a light source insertion/removal portion for inserting and removing the light source is provided in the housing of the device.

(Function) In other words, the present invention has the above-described configuration, so that when replacing the light source, there is no need to remove the glass plate that constitutes the object placement section as in the past, and the light source can be replaced easily. This can be done easily.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. FIGS. 1(a) and 1(b) show the appearance of the device of the present invention.
Figure 1(a) shows the state with the object holding cover open as seen diagonally from the front, and Fig. 1(b) shows the state with the object holding cover closed as seen diagonally from the rear. . 1 in the diagram
1 is a casing of the apparatus, and on the top surface of this casing 1, an object to be read holder 2 made of a transparent glass plate is provided. Further, on the upper surface of the housing 1, a read object holding cover 3 that presses down the read object A placed on the read object placement section 2 is hinged.

In addition, a scanning unit 4, which will be described later, is provided at the front of the upper surface of the housing 1.
A panel 5 is provided to indicate the operating status of the
A power switch 6 is provided on the right side of the housing 1.

As shown in FIG. 2, the scanning unit 4 includes a rod-shaped light source 9, which is surrounded by a reflector 8 at the back of the bracket 7. Optical system 10. and a photoelectric converter 11 attached thereto, and a carriage 12 that moves back and forth along the lower surface of the object to be read 2 by means of a carriage drive means (not shown).
It is installed in a removable manner.

The image data of the object A is read by moving the carriage 12 in the direction of arrow A in FIG. 2 with the light source 9 of the scanning unit 4 turned on. That is, the light source 9 irradiates light onto the object A placed on the object placement section 2, the reflected light is photoelectrically converted by the photoelectric converter 11, and image data of the entire object A is read. It turns out.

In addition, on the side surface of the housing 1, in a portion facing the initial position of the carriage 12, a light source insertion/removal portion 16 consisting of an opening closed by a cover 15 as shown in FIG. 1(b) is provided.
has been formed. Note that 17 is an external interface connector.

FIG. 3 shows a state in which the cover 15 is removed, and a first window 20 for light source replacement and a second window 21 for maintenance are exposed in the light source insertion/removal section 16.

FIG. 4 is an enlarged view of the first window 20 for replacing the light source in FIG. A connector 24 connects the carriage 12 to a heat insulating heater 23 (see FIG. 6) wrapped around the light source 9 whose luminous efficiency tends to change depending on the temperature of the outer periphery, and a photoelectric converter 11.
The gain adjustment volume 25, which determines the amplification factor of the image signal read by the scanner, and the offset adjustment volume 26, which also determines the offset of the amplifier, are exposed.

In addition, FIG. 5 shows the bracket 7, light source 9, and heat insulating heater 23.
, reflector 8. A light source unit 31 consisting of sockets 30, 30 is shown, and as shown in FIG. ing. That is, it can be removed from the carriage 12 by removing the connectors 22, 24 and screws 32, 32 of the bracket 7 shown in FIG.

Furthermore, when the light source 9 is pulled upward as shown by the arrow in FIG.
If the heat insulating heater 23 wrapped around is removed, the light source 9 becomes free, and the light source 9 is replaced in this state. Furthermore, a new light source 9 can be installed by following the above procedure in reverse.

Note that the carriage 12 is provided with a guide (not shown) so that the bracket 7 of the light source 9 does not wobble when inserted into the carriage 12.

This device assumes a light source 9 in which the amount of light decreases over time and changes, such as a fluorescent lamp, and takes a method called a light amount feedback method as a countermeasure for this.

This is a method in which a sensor is installed to observe the illuminance of the light source 9 itself, which is made of a fluorescent lamp, and the increase or decrease in the light amount of the light source 9 is fed back to adjust the value of the current flowing through the light source 9 so that the amount of light is always constant. .

Therefore, when the light source 9 is replaced, subtle changes in the positional relationship between the light source 9 and the sensor will have a large effect on the amount of light from the light source 9. That is, when the distance between the light source 9 and the sensor becomes shorter than in the previous state, the amount of light incident on the sensor increases, so the feedback circuit lowers the current of the light source 9 to reduce the amount of light.

Conversely, as the distance between the two increases, feedback is applied and the amount of light increases. Therefore, when replacing the light source 9, it is necessary to make adjustments so that a constant current flows through the light source 9.

The volume for this adjustment is the current adjustment volume 35 located within the second window 21 for maintenance as shown in FIGS. 3 and 7.

When the current value flowing through the light source 9 reaches a specified value, both LEDs indicated by 36 and 37 in the figure light up, indicating that the adjustment has been completed. Note that 38 is a window for adjusting the amount of light.

However, even if the current value flowing through the light source 9 is adjusted to be the same as before, the luminous efficiency of the light source 9 differs from one light source to another, so naturally the brightness with which the object A is illuminated also differs, and the amount of light felt by the image reading photoelectric converter 11. may also be different than before.

Therefore, it is necessary to newly adjust the amplification factor and offset of the analog circuit amplifier using the gain adjustment volume 25 and offset adjustment volume 26 shown in FIG. The 7-segment LED 4 in Fig. 7 shows how the gain and offset are adjusted using a method not described in this device.
0 can be monitored. In other words, the adjuster can make adjustments by turning the gain and offset volumes 25 and 26 while looking at the values on the 7-segment LED 40. Note that 41 is a maintenance panel.

In addition to the above-mentioned adjustments, the maintenance panel 41 can also execute a test mode of the apparatus.

According to the above embodiment, since the light source insertion/removal section 16 for inserting/removing the light source 9 is provided in the housing 1 of the apparatus, when replacing the light source 9, it is possible to replace the object to be read with the object mounting section 16 as in the conventional case. There is no need to remove the glass plate that makes up the glass plate, making it extremely easy to replace it.

The light source insertion/removal unit 16 also includes volumes 25 and 26 for adjusting the device, and a panel 41 for testing the device.
, and an operation window for operating the current adjustment volume 35 for adjusting the light intensity of the light source 9, so it is easy to adjust the light intensity after replacing the light source 9.
Readjustment of the circuit and testing of the device can be carried out extremely easily by operating the volume, etc. concentrated in the close vicinity, and therefore the user can replace the light source 9 by himself/herself without the need for a service person or the like. It also becomes possible.

[Effects of the Invention] As explained above, the present invention irradiates the object to be read with light from a light source and converts the light from the object into an electrical signal using a photoelectric converter. In an image reading device for reading images, a light source insertion/removal portion for inserting/removing the light source is provided in a housing of the device. Therefore, when replacing the light source, it is not necessary to remove the glass plate constituting the object to be read section as in the conventional case, and the light source can be replaced very easily.

[Brief explanation of the drawing]

FIG. 1(a) is an external perspective view of the device of the present invention with the object holding cover open, and FIG. 1(b) is an external perspective view of the device of the present invention with the object cover closed, viewed diagonally from behind. , second
The figure is an explanatory diagram schematically showing the configuration of the scanning unit section.
4 is a partially enlarged view of FIG. 3, FIG. 5 is a schematic perspective view of the light source unit, FIG. 6 is an explanatory diagram showing the state in which the light source unit is removed, and FIG. FIG. 7 is a partially enlarged view of FIG. 3. 1... Housing, 9... Light source, 11... Photoelectric converter,
16...Light source insertion/removal part that also serves as operation window, 25, 26.35
...Volume, 41...Panel, A...Object to be read (original). Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2 1 Figure 3

Claims (3)

[Claims] (1) In an image reading device that reads an object by irradiating the object with light from a light source and converting the light from the object into an electrical signal with a photoelectric converter, An image reading device comprising a light source insertion/removal section for inserting/removing a light source. (2) The image reading device according to claim 1, wherein the light source insertion/removal portion is located on a longitudinal extension of the light source. (3) The light source insertion/removal part doubles as a volume for adjusting the device, a panel for testing the device, and an operation window for operating the volume for adjusting the light intensity of the light source. An image reading device according to claim 1, characterized in that: