JP3605812B2 - Exposure control method for film scanner - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an exposure control method for a film scanner, and more particularly to an exposure control method for a film scanner that reads an image of a developed negative film using a line sensor.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a film image input device that captures a developed still photographic film with an image sensor such as a CCD, converts an image of the photographic film into an image signal, outputs the image signal to a monitor TV, and displays the film image is disclosed in WO90 / 04301. And JP-A-5-75922. Exposure control of this type of film scanner is generally performed by a mechanical diaphragm, and there is no method of controlling exposure by an electronic shutter of a CCD line sensor.
[0003]
On the other hand, in the specification of Japanese Patent Application No. 6-101189, a negative base (completely unexposed portion) of a film is read by a line sensor before reading a frame image, and a negative base R output from the line sensor is read. , G and B output voltages, the exposure control method of a film scanner for controlling the exposure time of a line sensor and the gain of an analog amplifier has been proposed.
[0004]
[Problems to be solved by the invention]
However, normally, there is a problem in a developed photographic film that there is no portion guaranteed as a negative base. In order to perform exposure control by the electronic shutter of the line sensor as described above, it is necessary to perform calibration based on the R, G, and B output voltages of a proper negative base. For that purpose, it is necessary to determine the optimum negative base part in the film. It is an extremely important matter whether to judge and read the data.
[0005]
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an area of a film scanner that identifies in advance a region having a high probability of being a negative base in a film, determines an optimal negative base from among the regions, and realizes correct exposure control. It is an object to provide a control method.
[0006]
[Means for solving the problem]
In order to achieve the above object, the present invention provides a developing method having a first reserved area reserved for a lab before a first frame and a second reserved area reserved for a lab after the last frame. The exposure control method of a film scanner in which a finished still photographic film is conveyed at a constant speed, a frame image of the film is read by a line sensor, and R, G, B output voltages of the line sensor are amplified by an analog amplifier. A first negative base area immediately before the first reserve area, a second negative base area immediately after the first reserve area, and a third negative base area immediately before the second reserve area in an initially set predetermined exposure state. At least one of a negative base region and a fourth negative base region immediately after the second reserve area is read by the line sensor. R, G, and B output voltages output from the analog amplifier are measured, and the gain or the gain of the analog amplifier is adjusted so that each of the measured maximum values of the R, G, and B output voltages matches a predetermined reference voltage. The invention is characterized in that the gain of the analog amplifier and the exposure time of the line sensor are controlled, and then the image of each frame is read.
[0007]
Further, in order to achieve the above object, the present invention provides a method for manufacturing a still photo film from a film cartridge having an opening through which a long still photo film enters and exits and a single spool around which the film is wound. The exposure control method for a film scanner, wherein the film image is conveyed at a constant speed, the frame image of the film is read by a line sensor, and the R, G, B output voltages of the line sensor are amplified by an analog amplifier. In the negative base area immediately before the reserved area reserved for the laboratory before the first frame of
W <X <L─W
Here, W is the maximum exposure width in the film length direction of a portion where the film can be exposed by light entering the cartridge through the opening.
L is the length that the film in the vicinity of the negative base region is wound around the spool once.
At least two positions separated by a distance (X) satisfying the above, reading is performed by the line sensor in each of the initially set predetermined exposure states, and R, G, and B output voltages output from the analog amplifier are measured. Then, a position having a large value among the measured R, G, and B output voltages is determined as a proper negative base position, and R, G, and B output from the analog amplifier when the determined proper negative base position is read. The gain of the analog amplifier or the gain of the analog amplifier and the exposure time of the line sensor are controlled so that each maximum value of the output voltage matches a predetermined reference voltage, and thereafter, an image of each frame is read. And
[0008]
Further, in order to achieve the object, the present invention compares the maximum value of the R output voltage measured at each position while keeping the exposure state and the gain of the analog amplifier constant, or at each of the positions. The proper negative base position of the film is determined based on the gain of the analog amplifier of the R channel at the time of performing the predetermined calibration.
[0009]
According to the present invention, first, a first negative base area immediately before a first reserve area of a film, a second negative base area immediately after a second reserve area, and a first reserve area in an initially set predetermined exposure state. At least one of the third negative base region immediately after and the fourth negative base region immediately before the second reserve area is read by a line sensor, and R, G, and B output voltages output from the analog amplifier are measured. Subsequently, the gain of the analog amplifier or the gain of the analog amplifier and the exposure time of the line sensor are controlled so that the measured maximum values of the R, G, and B output voltages coincide with a predetermined reference voltage. The image of each frame is read based on the exposure control. As a result, correct exposure control can be performed, and a frame image can be read properly.
[0010]
Further, reading is performed for a plurality of areas among the first to fourth negative base areas, and the maximum values of the R, G, and B output voltages measured for each negative base area are made to match a predetermined reference voltage. The gain of the analog amplifier or the gain of the analog amplifier and the exposure time of the line sensor are obtained. Then, among the plurality of negative base areas, the negative base area having the smallest gain or exposure time is determined as the negative base of the film, and the gain or gain and the exposure time of the negative base area are determined as the gain or gain of the film and the exposure time. Has been adopted. As a result, the negative base can be determined very accurately in a film for which the negative base is not guaranteed, and correct exposure control can be realized.
[0011]
When reading is performed for a plurality of negative base regions, the exposure condition and the gain of the analog amplifier are kept constant, and the maximum value of the R output voltage measured for each negative base region is compared and determined to determine the negative base region. ing. Further, as another embodiment of the present invention, the negative base region is determined by the magnitude of the gain of the analog amplifier of the R channel when a predetermined calibration is performed for each negative base region. Thus, when fogging occurs in the negative base due to red light such as light transmitted through the film, the output voltages of G and B are reduced due to the multilayer effect that suppresses G and B in order to improve the reproduction of R. Even when the negative base is increased, the negative base can be determined very accurately, and correct exposure control can be realized.
[0012]
Further, according to the present invention, the first negative base area immediately before the first reserve area of the film is read by the line sensor in the initially set predetermined exposure state, and the first R, G output from the analog amplifier is read. , B output voltage is detected and stored, and then the gain of the analog amplifier or the gain of the analog amplifier and the gain of the line sensor are adjusted so that each maximum value of the first R, G, and B output voltages matches a predetermined reference voltage. The exposure time is controlled. Then, the image of each frame is read based on the exposure control. After the reading of each frame image is completed, the exposure is returned to the initially set predetermined exposure state, and the reading of the fourth negative base area immediately after the second reserve area is performed. That is, the fourth R, G, B output voltages in the fourth negative base region output from the analog amplifier are measured. Then, the fourth R, G, B output voltage is compared with the stored first R, G, B output voltage, and when the fourth R, G, B output voltage is higher, Controlling the gain of the analog amplifier or the gain of the analog amplifier and the exposure time of the line sensor so that each maximum value of the fourth R, G, and B output voltages matches a predetermined reference voltage, After that, the image of each frame was read again. As described above, since the negative bases are measured for the first negative base region and the fourth negative base region having extremely high probability of being the negative base, and they are compared with each other, it is possible to easily determine the optimum negative base. Since each negative base area is read in accordance with the film transport sequence, the film can be transported efficiently.
[0013]
According to another aspect of the present invention, even when fogging occurs in the negative base area immediately before the reserved area of the film due to light incident from the opening of the film cartridge, the light is separated by a predetermined distance (X) within the negative base area. By performing the negative base measurement at at least two positions, it is possible to perform the measurement at an appropriate negative base position that does not correspond to the fog at least once.
[0014]
In other words, focusing on the fact that fog occurring in the negative base area immediately before the reserve area of the film periodically occurs in the winding cycle L of the film near the negative base area, the winding cycle L and the expected fog Using substantially W and
W <X <L─W
Since the calibration is performed at least twice at a position separated by the distance X that satisfies the relationship, the position of the fog can be avoided at least once. As a result, an optimum negative base can be easily determined, and accurate exposure control can be performed.
[0015]
Further, according to another aspect of the present invention, when fogging occurs in the negative base region immediately before the reserved area of the film due to light incident from the opening of the film cartridge, the film is wound and the inner layer portion has transmitted through the negative base in the inner layer portion. Red light causes fogging. At this time, since G and B are suppressed, which is called a multilayer effect, the outputs of G and B are apparently increased. Therefore, attention is paid to the R output voltage that does not cause the multilayer effect, and the negative base area is determined by measuring and comparing the R output voltages of the analog amplifiers in a plurality of areas. Therefore, the outputs of G and B affected by the multilayer effect are determined. To avoid performing calibration. As a result, an optimum negative base can be easily determined, and accurate exposure control can be performed.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a preferred embodiment of an exposure control method for a film scanner according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a perspective view showing a schematic configuration of an entire system including a film scanner to which a film scanner exposure control method according to the present invention is applied. As shown in FIG. 1, the film scanner 100 is formed in a rectangular parallelepiped shape, and a film cartridge tray 102 and a power switch 104 are provided on a front surface thereof. The film cartridge tray 102 is driven forward and backward when the film cartridge 110 is loaded / unloaded, so that the film cartridge 110 is stored or taken out.
[0017]
A keypad 120 and a monitor TV 109 are connected to the film scanner 100, and various operation signals for controlling the film scanner 100 are output from the keypad 120 via the signal cable 106 to the film scanner 100. Outputs a video signal to the monitor TV 109 via the signal cable 108. The details of the control of the film scanner 100 by the keypad 120 will be described later.
[0018]
FIG. 2 is a view showing an example of a film cartridge 110 applied to the film scanner 100 of FIG. As shown in FIG. 1, the film cartridge 110 has a single spool 112, and a photographic film 114 is wound around the spool 112. A perforation 114A indicating the position of each frame is formed in the photo film 114, and magnetic recording layers 115B and 115C are formed on the entire surface of the film or on the film edges. The magnetic recording layers 115B and 115C A camera having a magnetic head can record magnetic data indicating photographing data and the like for each frame.
[0019]
As the magnetic data to be recorded, for example, a frame number, a print format indicating one of a high-definition image, a panoramic image, and a normal image, a photographing date / time, and the like can be considered. be able to. In addition, a bar code indicating a film type, a frame number, and the like can be optically recorded on the photographic film 114 in addition to a frame region exposed by subject light.
[0020]
Here, of the one-roll film, a first lab reserve area LB1 and a magnetic track 115C are provided on the leading end side of the film with respect to the position of the first frame # 1, so that the film is located closer to the film than the last frame of the film. A second laboratory reserve area LB2 is provided on the rear end side.
The leading end of the film relative to the perforation 114A indicating the position of the first frame # 1 is referred to as a leader, and the magnetic track of the leader is referred to as a leader track 115C. The rear end side of the perforation 114A indicating the position of the first frame is called a frame portion, and the magnetic track of the frame portion is called a frame track 115B. The leader track 114C mainly records magnetic data of one entire roll, and the frame track 115B records magnetic data of each frame. Further, a bar code (not shown) representing an identification code (film ID) unique to the film is written on the edge of the leader portion of the film.
[0021]
The developed photographic film 114 is wound around a film cartridge 110 so that it can be stored.
By the way, the following four areas are likely to be the negative base of the photographic film.
(1) Area A immediately before the lab reserve area LB1
(2) Immediately after the laboratory reserve area LB1 and the area B between the area LB1 and the first frame # 1
{Circle around (3)} Immediately before the laboratory reserved area LB2, an area C between the area LB2 and the last frame # 40.
(4) Area D immediately after the lab reserve area LB2
Note that the area between the frames is expected to be exposed at the time of shooting, and thus is unlikely to be a negative base. In addition, since the vicinity of the leading edge of the film and the vicinity of the rear end of the film may be illuminated when the film is taken out in the laboratory, the probability of being a negative base is low.
[0022]
In the regions A to D, the probability of the negative base is considered to be higher in the order of D>A>C> B (see FIG. 2). Regions A and D are unlikely to be exposed during shooting, and particularly, region D is located at the innermost position of the cartridge, and thus has a very high possibility of being a negative base. On the other hand, both the areas B and C are likely to be exposed at the time of photographing. In particular, since the area B is on the leading end side of the film, the possibility is expected to increase.
[0023]
FIG. 3 is a block diagram showing an embodiment of the internal configuration of the film scanner 100. The film scanner 100 mainly includes a light source 130 for illumination, a photographing lens 136, a CCD circuit unit 140 including a CCD line sensor 142, a first signal processing circuit 151, a second signal processing circuit 152, a third signal processing circuit 153, and a memory. A control circuit 154, CCD buffers M1a and M1b, a display buffer M2, a central processing unit (CPU) 160, a film driving mechanism 170, an optical data reading device 180, a magnetic recording / reproducing device 182, and the like are provided.
[0024]
The light source 130 is, for example, a fluorescent lamp that is long in a direction perpendicular to the feeding direction of the film 114, and illuminates the film 114 via an infrared cut filter 132. The image light transmitted through the film 114 is imaged on the light receiving surface of the CCD line sensor 142 via the single focus photographing lens 136. During filming of the film image by the CCD line sensor 142, the film 114 is moved by the film driving mechanism 170 at a constant speed in the direction of arrow F (hereinafter, referred to as forward direction) or the direction of arrow R (hereinafter, referred to as reverse direction). However, the details of the film driving will be described later.
[0025]
The CCD line sensor 142 is disposed in a direction perpendicular to the film feeding direction, and the image light formed on the light receiving surface of the CCD line sensor 142 is charged for a predetermined time by each sensor having R, G, and B filters. It is stored and converted into R, G, B signal charges in an amount corresponding to the light intensity. The signal charges thus accumulated are read out to the shift register by a read gate pulse of a predetermined cycle applied from the CCD drive circuit 144, and are sequentially read out by a register transfer pulse.
[0026]
The CCD line sensor 142 is provided with a shutter gate and a shutter drain (not shown) adjacent to each light receiving unit. By driving the shutter gate with a shutter gate pulse, the electric charge accumulated in the light receiving unit is provided. To the shutter drain. That is, the CCD line sensor 142 is a CCD drive circuit. 144 It has a so-called electronic shutter function that can control the electric charge accumulated in the light receiving section according to the shutter gate pulse applied from the shutter.
[0027]
In the present embodiment, one line cycle of the read gate pulse is 1.6 ms, and the shutter gate pulse is controlled so as to be applied at a predetermined timing obtained by dividing the range of 576 ns to 1.6 ms into 255. . The driving of the CCD driving circuit 144 is controlled by the CPU 160, and the variable range of the shutter amount of the CCD line sensor 142 is controlled to 15% to 100% from the CPU 160 via the CCD driving circuit 144.
[0028]
The CCD line sensor 142 has, for example, a sensor for 1024 pixels in a direction orthogonal to the film feeding direction. The number of pixels in the same direction as the film feeding direction of one frame changes according to the film feeding speed when the period of the read gate pulse or the like of the CCD drive circuit 144 is not changed. The number of pixels at 1/2, 1, 8, and 16 times the feeding speed when the film image is taken in is 1,792, 896, 112, and 56 pixels.
[0029]
The signal charges read from the CCD line sensor 142 in this manner are clamped by the CDS clamp 146A and applied as R, G, B signals to the analog amplifier 146, where the gains of the R, G, B signals are adjusted. Controlled. This gain control will be described later (see FIG. 4).
The R, G, and B signals output from the analog amplifier 146 are dot-sequentialized by the multiplexer 148, converted into digital signals by the A / D converter 150, and then applied to the first signal processing circuit 151 and the CPU 160.
[0030]
The first signal processing circuit 151 includes a white balance adjustment circuit, a negative / positive conversion circuit, a γ correction circuit, an RGB synchronization circuit, and the like. , And outputs the synchronized R, G, and B signals to the second signal processing circuit 152.
FIGS. 5A to 5F are explanatory diagrams showing the gradation of the output signal of each unit in the first signal signal processing circuit 151. FIG.
[0031]
As shown in FIG. 5A, when a negative film in which a subject whose linear gradation increases linearly is photographed is imaged by the CCD line sensor 142, the output signals of R, G, and B output from the CCD line sensor 142 are as follows. The waveform as shown in FIG. 5B is obtained by the gamma of the negative film.
The first signal signal processing circuit 151 performs signal processing of black level, negative / positive inversion, white level, and gamma correction of input R, G, and B signals. The peak values (black level of the positive image) of the R, G, and B signals are adjusted by adding the offset values for each of the R, G, and B signals (see FIG. 5C).
[0032]
Subsequently, the negative-positive inversion circuit subtracts the offset R, G, and B signals from a predetermined peak value to perform negative-positive inversion. FIG. 5 (D) shows the R, G, B signals that have been negative-positive inverted. Next, white balance correction is performed by multiplying the negative-positive inverted R, G, and B signals by gain amounts for each of the R, G, and B signals based on a control signal applied from the CPU 160. That is, as shown in FIG. 5E, the other peak values (white level of the positive image) of the R, G, and B signals are adjusted. The gamma correction circuit adjusts the halftone of the R, G, and B signals and performs a predetermined gamma (γ = 0.45) by performing different gamma corrections on the R, G, and B signals that have been subjected to the white balance correction. ) (See FIG. 5F).
[0033]
The second signal processing circuit 152 has a matrix circuit, and based on input R, G, B signals, a luminance signal Y and a chroma signal C. _{r / b} And outputs them to the memory control circuit 154.
The memory control circuit 154 receives the luminance signal Y and the chroma signal C _{r / b} Control of writing / reading to / from the CCD buffer M1a or M1b, and the luminance signal Y and the chroma signal C stored in the CCD buffer M1a or M1b. _{r / b} Of the display buffer M2 is controlled. The details of the control of writing / reading to / from the CCD buffers M1a and M1b and the display buffer M2 will be described later (see FIG. 9).
[0034]
The luminance signal Y and the chroma signal C read from the display buffer M2 by the memory control circuit 154. _{r / b} Is applied to the third signal processing circuit 153. The third signal processing circuit 153 receives the input luminance signal Y and chroma signal C. _{r / b} , A color composite video signal of, for example, the NTSC system is generated and output to the video output terminal 158 via the D / A converter 156. The memory control circuit 154, the third signal processing circuit 153, and the D / A converter 156 are supplied with a synchronization signal of a predetermined period from the synchronization signal generation circuit 159, thereby synchronizing the respective circuits with each other. Video signal including the synchronizing signal is obtained.
[0035]
Further, a timing signal from a timing signal generation circuit 162 controlled by the CPU 160 is applied to the CCD circuit unit 140, the A / D converter 150, the first signal processing circuit 151, the second signal processing circuit 152, and the memory control circuit 154, respectively. As a result, each circuit is synchronized.
The CPU 160 captures dot-sequential R, G, B signals from the A / D converter 150 shown in FIG. 3 for all frames for each color, and adjusts the offset amount for each color signal and the color signal for adjusting the white balance. The gain adjustment amount is calculated, and the offset data indicating the offset amount for each color signal and the AE / AWB data indicating the gain adjustment amount are stored for each frame in the RAM 160A built in the CPU.
[0036]
The film drive mechanism 170 engages with the spool 112 of the film cartridge 110, and drives a forward / reverse rotation of the spool 112. And a means for disposing the film 114 between a capstan (not shown) and a pinch roller to feed the film 114 at a constant speed. The film supply unit drives the spool 112 of the film cartridge 110 in the clockwise direction in FIG. 3, and sends out the film 114 from the film cartridge 110 until the leading end of the film is wound by the film winding unit. .
[0037]
The optical data reader 180 includes a first optical sensor 180A for optically detecting the perforation 114A of the film 114, and a second optical sensor for optically detecting optical data such as a bar code written on the edge of the film. And a sensor 180B for processing optical data detected through the optical sensors 180A and 180B and outputting the processed data to the CPU 160.
[0038]
The magnetic recording / reproducing device 182 includes a magnetic recording / reproducing head 182A, reads magnetic data recorded on the magnetic recording layers 115B and 115C of the film 114 via the magnetic recording / reproducing head 182A, processes the magnetic data, and sends the processed magnetic data to the CPU 160. Then, after the write data supplied from the CPU 160 is converted into a signal suitable for magnetic recording, the signal is output to the magnetic recording / reproducing head 182A and recorded on the magnetic recording layers 115B and 115C of the film 114.
[0039]
Next, the operation of the film scanner will be described with reference to the flowcharts shown in FIGS.
First, the power of the film scanner is turned on (step 200), and the light source 130 is turned on. After the light amount of the light source 130 is stabilized (step 202), the film cartridge 110 is mounted on the film scanner 100 (step 204).
[0040]
Next, the electronic shutter of the CCD line sensor 142 is set to an initial value of 15%, and the amplifier gain is set to a predetermined value (initial value) (step 206).
Next, the photo film 114 is pulled out from the film cartridge 110, and when the optical data reader 180 detects the first perforation 114A of the film, the drawing of the film is stopped (region B in FIG. 2). Thereafter, the film is rewound by a predetermined amount, and returned to a position before the leader track 115C (region S in FIG. 2). Then, the magnetic data recorded on the leader track 115C is read by the magnetic recording / reproducing head 182A, and reaches the area A.
[0041]
The calibration is executed in this area A (steps 206 to 210). That is, the electronic shutter of the CCD line sensor 142 is set to the initial value of 15%, and the amplifier gain is set to the initial value (step 206).
In the initial setting state, in the area A, the negative base of the photographic film 114 is imaged by the CCD line sensor 142, and the output voltage of the amplifier 146G is measured. 146G , 146B are stored (step 208).
[0042]
Then, an error between the maximum value d of the G output voltage output from the amplifier 146G and a reference voltage (for example, 2 V) is read, and the exposure time of the electronic shutter is changed so that the maximum value d matches 2 V.
Next, as shown in FIG. 4, a gain control signal is output from the CPU 160 to the amplifiers 146R and 146B, and the maximum values of the R and B output voltages output from the amplifiers 146R and 146B are made equal to 2 V (step 210).
[0043]
By the way, in addition to the above, it is also conceivable to first measure the negative base in the area B and then measure the negative base in the area A. In this case, the R, G, and B output voltages measured and stored for each area are compared, and a negative base area having a large value is determined as an appropriate negative base area, and the R output from the analog amplifier when the negative base area is photographed. , G, and B output voltages are controlled so that the maximum values of the output voltages coincide with a predetermined reference voltage. Since the probability of the negative base is A> B, the negative base imaging in the area B can be omitted.
[0044]
Now, following the step 210, the first pre-scan is executed (step 212). That is, at the time of the first pre-scan, the film 114 is fed at a high speed of 148.0 mm / sec in the forward direction as shown in FIG. The AE / AWB data and the magnetic data are obtained by reading the magnetic data via the 182.
[0045]
When the first pre-scan on the forward path of the film transport is completed, the film 114 is pulled out to the last frame # 40 and reaches the area C (see FIG. 2). The film 114 is further pulled out from the position, and the R, G, and B output voltages in a state where the electronic shutter and the amplifier gain are again set to the initial values in the region D To The measurement is performed (steps 213 and 214).
[0046]
Then, the output voltage is compared with the R, G, B output voltages based on the area A stored before the first prescan, and the larger value is determined as the optimum negative base of the film (step 216).
By the way, in addition to the above, after the first pre-scan is completed, it is conceivable to first measure the negative base in the area C and then measure the negative base in the area D. In this case, the R, G, and B output voltages measured and stored for each area are compared, and a negative base area having a large value is determined as an appropriate negative base area, and the R output from the analog amplifier when the negative base area is photographed. , G, and B output voltages are controlled so that the maximum values of the output voltages coincide with a predetermined reference voltage. Since the probability of being a negative base is D> C, measurement of the negative base in the area C can be omitted.
[0047]
If it is determined in step 216 that the proper negative base is that of the region D, the calibration is performed based on the measurement values obtained from the proper negative base, and then the first pre-scan is performed ( (Step 222) Then, the second pre-scan is executed on the return path (Step 224). On the other hand, if it is determined that the proper negative base is that of the area A, the state is returned to the state of the step 210 (step 221), and the second prescan is executed (step 224).
[0048]
FIG. 4 illustrates a case where the exposure time of the electronic shutter is controlled based on the G output voltage of the negative base R, G, and B output voltages, and the gain of the analog amplifier is controlled based on the R and B output voltages. As described above, the calibration method is not limited to this. The electronic shutter and the analog amplifier gain are set to initial values (step 213), the negative base is imaged by the CCD line sensor 142, and the image is output from the CCD line sensor 142. It is also possible to increase the gain for each signal by feedback control so that each of the maximum values of the R, G, and B output voltages becomes the reference voltage 2V (steps 210, 220, 221).
[0049]
In this case, a gain control signal is output from the CPU 160 to each of the amplifiers 146R, 146G, and 146B, and calibration is performed by making each of the maximum values of the R, G, and B output voltages coincide with the reference voltage 2V.
In FIG. 4, an appropriate negative base area is determined based on the magnitudes of the R, G, and B output voltages stored corresponding to each area. However, the present invention is not limited to this. Is performed, the gain in each area is compared, the area having the smallest value is determined as an appropriate negative base area, and the gain of the negative base area can be adopted as the appropriate gain of the film.
[0050]
In the second pre-scan (step 224), the film 114 is rewound in the reverse direction at a high speed of 74.0 mm / sec as shown in FIG. At the time of capturing the image data, the CPU 160 controls the electronic shutter mechanism of the CCD line sensor 142 based on the AE / AWB data stored in the RAM 160A. That is, the amount of exposure is adjusted by controlling the charge accumulation time in the CCD line sensor 142 via the CCD drive circuit 144.
[0051]
Further, the CPU 160 causes the first signal processing circuit 151 to adjust the offset amounts and the white balance of the R, G, and B signals for each frame. That is, the CPU 160 outputs the offset data for each color signal of each frame stored in the RAM 160A to the first signal processing circuit 151, and the first signal processing circuit 151 performs dot-sequential R, G, B based on the offset data. Adjust the signal offset. Similarly, CPU 160 outputs AE / AWB data for each color signal of each frame stored in RAM 160A to first signal processing circuit 151, and first signal processing circuit 151 performs dot-sequential processing based on the AE / AWB data. Adjust the gain of the R, G, B signals.
[0052]
Since the image data of each frame is adjusted based on the AE / AWB data and the like, good image data can be captured regardless of the shooting conditions of each frame. At the same time, more detailed AE / AWB data is obtained, rewritten and stored in the RAM 160A.
The image data of each frame adjusted in this manner, that is, the luminance signal Y and the chroma signal C output from the second signal processing circuit 152 _{r / b} Are sequentially stored in the index image buffer M1a via the memory control circuit 154. In this case, as shown in FIG. 8, the film 114 is fed at a speed eight times the feeding speed at the time of capturing a standard film image, so that the number of pixels in the same direction as the film feeding direction of one frame is set. Is 112 pixels (see FIG. 9A). The CCD line sensor 142 has a sensor for 1024 pixels in the direction orthogonal to the film feeding direction as described above. However, the CCD line sensor 142 is orthogonal to the film feeding direction for one frame by thinning out to 1/16. The number of pixels in the direction is 64 pixels.
[0053]
The index image buffer M1a is a non-volatile memory having a storage capacity for storing data of 512 × 1024 pixels, as shown in FIG. 9 (A), thereby providing 5 × 4 × 2 (= 40) frames. Image data can be stored. That is, the index image buffer M1a stores the image data indicating the index image for 40 frames.
[0054]
The display buffer M2 has a storage capacity of storing 512 × 1024 pixel data as shown in FIG. 9B, but when storing the image data indicating the index image, one frame of pixel data is stored. Is enlarged to 73 × 128 and stores image data for 5 × 4 (= 20) frames. When displaying the index image on the monitor TV 109, an area of 480 × 640 pixels at the upper left of the display buffer M2 is read (see FIGS. 9B and 9C).
[0055]
Now, in the index image buffer M1a, as shown in FIG. 9A, the image data of each frame is sequentially stored from the upper left storage area to the right in the reading order of the image data of each frame during the scanning, When four frames are stored, the data is sequentially stored again from the storage area down by one line toward the right side. When five rows (4 × 5 = 20 frames) are stored, the data is similarly stored in the storage area for the next 20 frames.
[0056]
Even during the above-described storage operation in the index image buffer M1a, the contents stored in the index image buffer M1a are transferred to the display buffer M2.
Since only 20 frames of image data can be stored in the display buffer M2 at one time, when the image data of the 21st frame is input to the index image buffer M1a, the display buffer M2 is scrolled so that the index image is scrolled upward. Rewriting and reading of image data are performed. For example, when the image data of the 21st frame is input to the index image buffer M1a, the image data of the storage area for one row of the frame numbers 1 to 4 in the display buffer M2 is cleared, and the image data of the 21st frame is written. At the same time, the scan start address at the time of outputting the video signal is changed to the second row. As a result, the index image scrolled upward by one line is displayed on the monitor TV 109. In this way, the image data of all frames Index image buffer M1a Is scrolled downward or the screen is switched so that the index images of frame numbers 1 to 20 are displayed on the monitor TV 109 again.
[0057]
By the way, the CPU 160 sets the frame numbers to 1, 2,... In the reading order of the image data of each frame at the time of the scan, and outputs a character signal indicating the frame number of each frame so that the frame number is changed. The superimposed index image is displayed.
The index image is created as described above and displayed on the monitor TV 109 (FIG. 7, step 310).
[0058]
Subsequently, it is determined whether or not the automatic reproduction is selected by a key operation or the like (step 318). If the automatic reproduction is not selected in step 318, the keypad 120 is used while viewing the index image, and editing necessary for displaying one frame on the monitor TV 109 in an interactive manner and designation of other image reproduction processing information are performed. Perform (Step 320).
[0059]
Next, an example in the case of displaying and editing each frame will be described.
In this case, whether or not to display each frame is selected (step 322), and when displaying a frame, a display frame number is input (step 324). Thereafter, as shown in FIG. 8, the film 114 is fed one frame in the forward direction at 9.25 mm / sec, and the frame of that frame number is scanned (main scan) (step 326). At the time of this scan, image data is taken into the image data buffer M1b via the CCD line sensor 142.
[0060]
At the time of the main scan, the brightness information of the frame image to be read is read from the RAM 160A, and the R, G, and B output voltages output from the analog amplifier 146 to the A / D converter 150 are read based on the brightness information. The exposure time of the CCD line sensor 142 is controlled so that the maximum value becomes the maximum value 2V obtained by imaging the negative base. For example, when the dynamic range of the analog amplifier 146 when imaging the negative base is 255 digital values (8 bits) and the reference maximum value of the image data read from the RAM 160A is 127 digital values. Sets the exposure time of the CCD line sensor 142 to twice (34%) and captures the frame image.
[0061]
As described above, when capturing image data, the CPU 160 adjusts the image data of each frame based on the AE / AWB data or the like stored in the RAM 160A, and thus captures good image data regardless of the shooting conditions of each frame. be able to.
Further, the number of pixels for one frame taken in the image data buffer M1b in this manner is 512 × 896 pixels as shown in FIG. 9D. That is, the CCD output of the CCD line sensor 142 having a sensor for 1024 pixels is thinned out to 1/2 at the time of the main scan, whereby the number of pixels in the direction orthogonal to the film feeding direction for one frame is set to 512. By reducing the feeding speed to 1/8 of that at the time of capturing the image data of the index image, the number of pixels (112 pixels) in the same direction as the film feeding direction of one frame of the index image is set to 896 pixels. .
[0062]
The image data for one frame captured in the image data buffer M1b as described above is transferred to the display buffer M2, and the content of the display buffer M2 is repeatedly read out, so that an image of one frame is displayed on the monitor TV 109. Is displayed. The transfer of the index image buffer M1a and the image data buffer M1b to the display buffer M2 can be switched at any time by a switch.
[0063]
In the one-frame playback menu setting mode, the selected frame number is displayed on the upper left of the screen of the monitor TV 109, and characters indicating a setting menu and the like necessary for editing one frame are displayed on the right side of the screen of the monitor TV 109. The menu is selected by using the keypad 120 to specify a menu to be executed in the same manner as the editing using the index image.
[0064]
When the editing of the display frame is completed (step 328), the film 114 is fed in the reverse direction at a high speed of 148.0 mm / sec as shown in FIG. 8, and during this feeding, the magnetic recording layer 115B of the film 114 is Magnetic data read from the memory 115C and stored in the RAM 160A, data indicating the contents of editing using the index image, data indicating the contents of editing using the display frame, and the like are magnetic data as the magnetic recording layer 115B of the film 114, The image is recorded again on 115C (step 330), and after the rewinding, the film cartridge 110 is taken out (step 332).
[0065]
On the other hand, if the editing using the display frame is not to be executed in step 322, the process proceeds to steps 340 and 342, as in steps 330 and 332, where the film 114 is written on the magnetic recording layers 115B and 115C, and the film cartridge is The removal of 110 is performed.
When automatic reproduction is selected in step 318, images of a plurality of frames of a one-roll film are automatically reproduced sequentially based on the automatic reproduction information stored in the RAM 160A (step 348). When the automatic reproduction is completed, the magnetic data is recorded again on the magnetic recording layers 115B and 115C at the time of rewinding the film (Step 350), and after the rewinding is completed, the film cartridge 110 is taken out (Step 352).
[0066]
In the present embodiment, the R, G, and B output voltages are measured in the area A in relation to the film transport sequence, exposure control is performed, pre-scanning is performed, and then, in the area D, R, G, and B are again measured. Although the case where the output voltage is measured has been described, the present invention is not limited to this, and the R, G, and B output voltages are measured in at least one of the regions A to D, and the maximum value of each of the R, G, and B output voltages is measured. It is also conceivable to control the gain or the gain and the exposure time of the line sensor so that is equal to the reference voltage. In particular, since the regions A and D have a high probability of being negative-based, it is conceivable to adopt the result of calibration in the regions A or D as the film calibration.
[0067]
FIG. 10 is a diagram for explaining the second embodiment of the present invention. In the embodiment shown in FIG. 10, calibration is performed twice at a position separated by a predetermined distance X in a region E immediately before the laboratory reserve area LB1 having a high probability of being a negative base. The same or similar components have the same reference characters allotted, and description thereof will be omitted.
[0068]
The film cartridge 110 is provided with an opening 110A for inserting and removing the film 114. The opening 110A is opened and closed by a light-shielding door (not shown).
The film 114 wound and stored in the film cartridge 110 is exposed to light incident from the opening 110A, and fogs 118a, 118b, and 118c may occur.
[0069]
That is, the portion near the leading end of the film 114 is the outermost periphery of the winding, and the light is directly applied, so that a relatively large fog 118a is generated. The maximum width of the fog 118a is W. At a position wound by just one round L from the fog 118a, a fog 118b smaller than the fog 118a is generated by light transmitted through the outermost film.
[0070]
Similarly, a fog 118c smaller than the fog 118b is formed at a position where the fog 118b is further wound by exactly one rotation L.
Thus, fog portions 118a, 118b, 118c,... Are generated at each position of the winding cycle L. Note that the position of the outermost fogging portion 118a on the film is not uniquely determined, but occurs at an arbitrary position depending on how the film is wound up.
[0071]
Therefore, if the calibration is performed only once at a fixed position in the region E, there is a possibility that the calibration is performed at the positions of the fogs 118a, 118b, 118c..., And an appropriate result cannot be obtained. Inconvenience occurs. Therefore, in the embodiment shown in FIG. 10, an appropriate negative base calibration is always performed regardless of the presence or absence of the fogs 118a, 118b, and 118c as described above.
[0072]
That is, when the photographic film 114 is pulled out from the film cartridge 110 and the optical data reader 180 detects the first perforation 114A of the film, the drawing of the film is stopped, and then the film is rewound by a predetermined amount, and the position P1 shown in FIG. Return to Then, the same calibration (first calibration) as the method described in the above embodiment is executed in this area P1, and then the second calibration is performed again at the position P2 separated by the distance X.
[0073]
The distance X is given by the following equation (1).
W <X <L─W (1)
When the condition is satisfied, at least one of the positions P1 and P2 is a position other than the fog portions 118a, 118b and 118c, so that an appropriate negative base measurement can be performed.
[0074]
The exposure time of the electronic shutter or the gain of the analog amplifier based on the first calibration is compared with the exposure time of the electronic shutter or the gain of the analog amplifier based on the second calibration. Adopt appropriate negative base gain or gain and exposure time.
On the other hand, as shown in FIG. 10, when fogging occurs in the negative base area immediately before the reserved area of the film due to the light incident from the opening of the film cartridge, the fogging of the film causes fogging due to the red light transmitted through the negative base in the inner layer part. However, at this time, the suppression of G and B, which is called the multilayer effect, tends to occur.
[0075]
That is, as shown in the graph of FIG. 11, the light that reaches the exposure area on the inner circumference side (the second and third rounds in the film cartridge) by the negative base orange mask has a strong R component. , B hardly reach. Accordingly, in the inner peripheral side exposure area, only R develops color, and G and B components do not develop color. Therefore, an overlay effect occurs here, and the density of G and B becomes lower than the original negative base (transmission). When the negative base is detected from the respective concentrations of R, G, and B, there is a possibility that an appropriate negative base is erroneously detected. In this case, since the outputs of G and B apparently increase due to the layering effect, there is a problem that proper calibration cannot be performed.
[0076]
Therefore, in the third embodiment of the present invention, an appropriate negative base area is determined by comparing the maximum value of the R output voltage of the line sensor in a plurality of areas. That is, while the electronic shutter and the analog gain are kept constant, the maximum value of the R output voltage in a plurality of regions is compared, and the region where the R output voltage is the highest is determined as an appropriate negative base region. Then, the same calibration as that of the method described in the second embodiment is performed so that the maximum values of the R, G, and B output voltages of the line sensor that reads the negative base region respectively match the predetermined reference voltages. Then, an appropriate negative base gain of the film or a gain and an exposure time are adopted.
[0077]
In the second embodiment, the case where the calibration is performed in the order of the positions P1 and P2 has been described. However, the present invention is not limited to this, and the calibration is performed in the order of the positions P2 and P1 from the side closer to the laboratory reserve area LB1. Is also good.
Next, as shown in FIG. 12, calibration is performed in the order of positions P2 and P1 from the side closer to the laboratory reserved area LB1, and if the position P2 is a proper negative base, the calibration at the position P1 is omitted. A fourth embodiment of the present invention that can be used will be described.
[0078]
As shown in the flow chart of FIG. 13, the power of the film scanner is turned on to turn on the light source 130, and after the light amount of the light source 130 is stabilized (step 401), the film cartridge 110 is mounted on the film scanner 100 (step 404). .
Next, the electronic shutter of the CCD line sensor 142 is set to an initial value of 15%, and the amplifier gain is set to a predetermined value (initial value) (step 405). Next, the photographic film 114 is pulled out from the film cartridge 110, and when the optical data reader 180 detects the first perforation 114A of the film, the drawing of the film is stopped (Step 406).
[0079]
Subsequently, as shown in FIG. 12, the film is rewound by a predetermined distance Y and moved to a predetermined position P2 immediately before the lab reserve area LB1 (step 407).
Then, the first negative base calibration is executed using this position P2 as an appropriate negative base (step 410). That is, the negative base at the position P2 is imaged by the CCD line sensor 142, and the output voltage of the line sensor 142 is measured. Then, an error between the maximum value d of the G output voltage output from the CCD line sensor 142 and a reference voltage (for example, 2V) is read, and the exposure time of the electronic shutter is changed so that the maximum value d becomes equal to 2V. Next, as shown in FIG. 4, a gain control signal is output from the CPU 160 to the amplifiers 146R and 146B so that the maximum values of the R and B output voltages are made equal to 2V. Then, the R output voltage (output P2) is stored (step 411).
[0080]
Next, as shown in FIG. 12, the film is rewound by the predetermined distance X shown in the above-mentioned equation (1) and moved to the position P1 (step 412). The negative base at the position P1 is imaged by the CCD line sensor 142, and the R output voltage (output P1) of the line sensor 142 is read (step 415). At this time, the value of the electronic shutter and the gain of the analog amplifier are maintained as adjusted in step 410.
[0081]
Next, the output P2 stored in step 411 is compared with the output P1 read in step 415 (step 418).
(Output P2) <(Output P1) × {(100−δ)%} (2)
Where δ is a predetermined value indicating the allowable range
Is satisfied, the position P1 is determined to be a proper negative base, the second negative base calibration is executed again in step 420, and then the process proceeds to step 310 shown in FIG.
[0082]
On the other hand, if the equation (2) is not satisfied in step 418, the second negative base calibration is omitted, and the process proceeds to step 310 shown in FIG.
Actually, in most cases, since the position P2 is a proper negative base, the calibration at the position P1 can be omitted. Note that the output P2 is adjusted so as to be the reference voltage by the first negative base calibration, so that the output P2 need not be stored in step 411.
[0083]
As shown in FIG. 12, a recording area 115D for recording optical information such as a bar code is provided in the film 114 in correspondence with each frame and the lab reserve area LB1, and the lab reserve area LB1 is provided. Is also provided immediately before. Therefore, it is preferable to set the distances X and Y such that the positions P1 and P2 for reading the negative base are both located in the recording area 115D immediately before the laboratory reserve area LB1. This is because optical information such as a barcode is recorded in the recording area 115D, so that the possibility of unnecessary exposure is low. Further, the position P1 is more preferably a position (including a run distance) necessary for reading magnetic information.
[0084]
In the second and fourth embodiments, the case where the calibration is performed at two positions P1 and P2 has been described. However, the calibration may be performed at two or more positions.
[0085]
【The invention's effect】
As described above, according to the exposure control method of the film scanner according to the present invention, at least the negative base area immediately before and immediately after the first and second reserve areas which are expected to have a high probability of being the film negative base. One area is read by the line sensor, and the R, G, B output voltages output from the line sensor are measured, and each of the maximum values of the obtained R, G, B output voltages is matched with a predetermined reference voltage. By controlling the gain of the analog amplifier or the gain of the analog amplifier and the exposure time of the line sensor, and reading the image of each frame based on the exposure control, it is optimal for a film whose negative base is not guaranteed. A negative base can be reliably determined, and correct exposure control can be realized.
[0086]
Further, reading is performed for a plurality of areas of the negative base area immediately before and after the first and second reserve areas, and the maximum values of the R, G, and B output voltages output from the respective line sensors are determined by a predetermined value. The gain of the analog amplifier or the gain of the analog amplifier and the exposure time of the line sensor are determined so as to match the reference voltage. Of these, the negative base area having the smallest gain or the smallest exposure time is determined as the negative base of the film. By using this, it is possible to determine an appropriate negative base for a film for which a negative base is not guaranteed.
[0087]
Further, it is possible to easily determine the most suitable negative base by measuring the negative bases of the first negative base region and the fourth negative base region, which have extremely high probability of being the film negative base, and comparing them. Since each negative base area is read in accordance with the film transport sequence, the film can be transported efficiently.
[0088]
Further, according to the exposure control method of the film scanner according to the present invention, even when fog occurs in the negative base area immediately before the reserved area of the film due to light incident from the opening of the film cartridge, the predetermined distance (in the negative base area) By performing the negative base measurement at at least two locations separated by X), it is possible to perform the measurement at an appropriate negative base position that does not correspond to the fog at least once.
[0089]
In addition, when determining the negative base region, by comparing and determining the R output value of each region, it is possible to easily perform appropriate calibration while avoiding the influence of the layering effect.
Further, since the calibration is performed after comparing the maximum value of the R output voltage, the time required for the calibration can be reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a schematic configuration of an entire system including a film scanner to which a film scanner exposure control method according to the present invention is applied.
FIG. 2 is a diagram showing an example of a film cartridge applied to the film scanner of FIG.
FIG. 3 is a block diagram showing an embodiment of the internal configuration of the film scanner of FIG. 1;
FIG. 4 is a block diagram for explaining an example of signal processing in the CCD circuit unit 140 of FIG. 3;
FIGS. 5A to 5F are explanatory diagrams showing gradations of output signals of respective units of a first signal processing circuit 151. FIGS.
FIG. 6 is a flowchart showing a first embodiment of a film scanner exposure control method according to the present invention;
FIG. 7 is a flowchart used to explain the operation of the film scanner shown in FIG. 1;
FIG. 8 is a diagram showing an example of a film transport sequence of the film transported by the film scanner shown in FIG.
9 (A) to 9 (D) are diagrams showing storage areas of an index image buffer, an image data buffer, a display buffer and a display screen of a monitor TV in the film scanner shown in FIG. 3;
FIG. 10 is a diagram for explaining a second embodiment of the present invention.
FIG. 11 is a graph showing a negative base concentration used for explaining a third embodiment of the present invention.
FIG. 12 is a diagram for explaining a fourth embodiment of the present invention.
FIG. 13 is a flowchart of an exposure control method of the film scanner according to the fourth embodiment of the present invention.
[Explanation of symbols]
100 ... film scanner
110 ... Film cartridge
114 ... Photo film
118a, 118b, 118c: fog portion
142 ... CCD line sensor
144: CCD drive circuit
146… Analog amplifier
150 ... A / D converter
160 ... Central processing unit (CPU)
160A RAM
LB1, LB2 ... Reserve area for laboratory

Claims (12)

A developed still photographic film having a first reserved area reserved for the lab before the first frame and a second reserved area reserved for the lab after the last frame is transported at a constant speed. In a film scanner exposure control method in which a frame image of the film is read by a line sensor and R, G, and B output voltages of the line sensor are amplified by an analog amplifier, a first image immediately before the first reserve area is provided. At least a negative base region, a second negative base region immediately after the first reserve area, a third negative base region immediately before the second reserve area, and a fourth negative base region immediately after the second reserve area. One is read by the line sensor, and the R, G, B output voltages output from the analog amplifier are measured,
Controlling the gain of the analog amplifier or the gain of the analog amplifier and the exposure time of the line sensor so that each of the measured maximum values of the R, G, and B output voltages matches a predetermined reference voltage;
Then, an exposure control method for the film scanner, wherein an image of each frame is read. In a plurality of areas among the first to fourth negative base areas, an appropriate negative base area is determined based on the magnitudes of the R, G, and B output voltages acquired in the initially set predetermined exposure state,
The gain of the analog amplifier or the gain of the analog amplifier is set such that the maximum value of each of the R, G, and B output voltages output from the analog amplifier at the time of reading the determined appropriate negative base area matches a predetermined reference voltage. Control the exposure time of the line sensor,
2. An exposure control method for a film scanner according to claim 1, further comprising reading an image of each frame. 3. The exposure control method for a film scanner according to claim 2, wherein a maximum value of each R output voltage at each position acquired in a plurality of regions among the first to fourth negative base regions is compared,
The gain of the analog amplifier or the gain of the analog amplifier is adjusted so that the maximum value of each of the R, G, and B output voltages output from the analog amplifier in a region where the maximum value of the R output voltage is the largest value matches a predetermined reference voltage. Controlling the gain of the analog amplifier and the exposure time of the line sensor,
Then, an exposure control method for the film scanner, wherein an image of each frame is read. Regarding the R, G, and B output voltages acquired in a plurality of regions among the first to fourth negative base regions, the maximum value of each of the output voltages of R, G, and B for each negative base region is a predetermined reference voltage. The gain of the analog amplifier or the gain of the analog amplifier and the exposure time of the line sensor are controlled so as to match, and the gain of the analog amplifier or the gain of the analog amplifier and the exposure time of the line sensor at this time are Memorize corresponding to multiple areas,
The smallest value of the gain or exposure time stored corresponding to the plurality of regions is adopted as an appropriate gain or gain and exposure time of the film,
Based on this, the gain of the analog amplifier or the gain of the analog amplifier and the exposure time of the line sensor are adjusted so that each maximum value of the R, G, and B output voltages output from the analog amplifier matches a predetermined reference voltage. And control the
2. An exposure control method for a film scanner according to claim 1, further comprising reading an image of each frame. 5. The exposure control method for a film scanner according to claim 4, wherein a gain of an analog amplifier of the R channel among the gains stored corresponding to a plurality of areas among the first to fourth negative base areas is compared. ,
The gain of the analog amplifier or the gain of the analog amplifier and the exposure time of the line sensor stored in correspondence with the area where the gain of the analog amplifier of the R channel indicates the smallest value are determined by using the appropriate negative base gain or gain of the film. Adopted as exposure time,
Based on this, control the gain of the analog amplifier or the gain of the analog amplifier and the exposure time of the line sensor,
Then, an exposure control method for the film scanner, wherein an image of each frame is read. In the initially set predetermined exposure state, the first negative base area immediately before the first reserve area is read by the line sensor, and the first R, G, and R of the first negative base area output from the analog amplifier are read. Measuring the B output voltage and storing the first R, G, B output voltage;
The gain of the analog amplifier or the gain of the analog amplifier and the exposure time of the line sensor so that each maximum value of the first R, G, and B output voltages output from the analog amplifier matches a predetermined reference voltage. Control the
After that, read the image of each frame,
Next, in a predetermined initial exposure state again, the fourth negative base area immediately after the second reserve area is read by the line sensor, and the fourth negative base area in the fourth negative base area output from the analog amplifier is read. R, G, B output voltage of
When the fourth R, G, B output voltage is higher than the stored first R, G, B output voltage, each maximum value of the fourth R, G, B output voltage is a predetermined value. Controlling the gain of the analog amplifier or the gain of the analog amplifier and the exposure time of the line sensor to match the reference voltage,
2. An exposure control method for a film scanner according to claim 1, further comprising reading an image of each frame. 7. The exposure control method for a film scanner according to claim 6, wherein the maximum value of the fourth R output voltage in the fourth negative base region is equal to the maximum value of the stored first R output voltage in the first negative base region. If it is larger than the maximum value, the gain of the analog amplifier or the gain of the analog amplifier and the exposure of the line sensor are adjusted so that each maximum value of the fourth R, G, and B output voltages matches a predetermined reference voltage. Control the time and
Then, an exposure control method for the film scanner, wherein an image of each frame is read. The still photo film is transported at a constant speed from a film cartridge having an opening through which a long still photo film enters and exits and a single spool around which the film is wound, and a frame image of the film is lined up. In an exposure control method of a film scanner, the read voltage is read by a sensor and the R, G, B output voltages of the line sensor are amplified by an analog amplifier.
In the negative base area immediately before the reserved area reserved for the laboratory before the first frame of the still photo film, the following equation W <X <L─W
Here, W is the maximum exposure width L in the film length direction of the portion where the film can be exposed by the light entering the cartridge from the opening, and is the length that the film near the negative base region is wound around the spool one round. At least at two positions separated by a distance (X) satisfying the above, reading is performed by the line sensor in a predetermined initial exposure state,
Measuring R, G, B output voltages output from the analog amplifier,
A position having a large value among the measured R, G, B output voltages is determined as an appropriate negative base position,
The gain of the analog amplifier or the gain of the analog amplifier is adjusted so that the maximum value of each of the R, G, and B output voltages output from the analog amplifier at the time of reading the determined appropriate negative base position matches a predetermined reference voltage. Control the exposure time of the line sensor,
Then, an exposure control method for the film scanner, wherein an image of each frame is read. 9. The exposure control method for a film scanner according to claim 8, wherein a maximum value of each R output voltage at each position is compared.
The gain of the analog amplifier or the gain of the analog amplifier and the gain of the line sensor are adjusted so that the maximum value of each of the R, G, and B output voltages output from the analog amplifier at the position indicating the largest value matches a predetermined reference voltage. Control the exposure time and
Then, an exposure control method for the film scanner, wherein an image of each frame is read. The still photo film is transported at a constant speed from a film cartridge having an opening through which a long still photo film enters and exits and a single spool around which the film is wound, and a frame image of the film is lined up. In an exposure control method of a film scanner, the read voltage is read by a sensor and the R, G, B output voltages of the line sensor are amplified by an analog amplifier.
A line sensor reads a first position in a negative base area immediately before a reserved area reserved for a laboratory before a first frame of the still photo film,
A gain of the analog amplifier or a gain of the analog amplifier and an exposure time of a line sensor for controlling the maximum value of each of the R, G, and B output voltages output from the analog amplifier to be equal to a predetermined reference voltage. Perform the first calibration,
Thereafter, in the negative base area immediately before the reserve area, and from the first position, the following equation W <X <L─W
Here, W is the maximum exposure width L in the film length direction of the portion where the film can be exposed by the light entering the cartridge from the opening, and is the length that the film near the negative base region is wound around the spool one round. A second position separated by a distance (X) that satisfies the above is read by the line sensor while the first calibration is performed,
When the R, G, and B output voltages output from the analog amplifier at the time of reading at the second position increase, each of the maximum values of the R, G, and B output voltages output from the analog amplifier becomes a predetermined value. Performing a second calibration to control the gain of the analog amplifier or the gain of the analog amplifier and the exposure time of the line sensor so as to match the reference voltage;
If the R, G, B output voltages output from the analog amplifier are equal or smaller, the second calibration is omitted,
Then, an exposure control method for the film scanner, wherein an image of each frame is read. 11. The exposure control method for a film scanner according to claim 10, wherein when the R output voltage among the R, G, B output voltages output from the analog amplifier at the time of reading at the second position is equal to or smaller than the R output voltage. Omitting the second calibration,
Then, an exposure control method for the film scanner, wherein an image of each frame is read. 11. The exposure control method for a film scanner according to claim 10, wherein the first position and the second position separated by the distance (X) are within a recording area where optical information such as a bar code is recorded on the film. A film scanner exposure control method.

Images